prototypey.org - atproto lexicon typescript toolkit - mirror https://github.com/tylersayshi/prototypey
Merge pull request #7 from tylersayshi/infer-fixing
fix infer to be a close match of what's simplified from the json given
next will be to do a final pass to replace ref types with their definition and return the final thing 🎉
+1055
-116
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.github/workflows/ci.yml
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.github/workflows/ci.yml
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README.md
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README.md
···
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> [!WARNING]
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> this project is in the middle of active initial development and not ready for
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> use. there will be updates posted [here](https://bsky.app/profile/tylur.dev)
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> if you'd like to follow along! or checkout the [todo.md](./todo.md)
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> if you'd like to follow along!
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notebook/skip-uniontotuple-optimization.md
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notebook/skip-uniontotuple-optimization.md
···
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# Skip UnionToTuple When Empty - Optimization Notes
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## Starting Point
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**Initial Benchmark Results (from todo.md):**
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- Simple object (2 properties): **578 instantiations** (baseline: 62, 9.3x over)
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- Complex nested (3 defs): **971 instantiations** (baseline: 124, 7.8x over)
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**Target:** Reduce to ~200-250 instantiations for simple case
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## Before This Optimization
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Previous optimizations had already been applied (likely "Make Prettify Lazy"):
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- Simple object: **275 instantiations**
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- Complex nested: **542 instantiations**
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## The Problem
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The `ObjectResult` and `ParamsResult` types were computing `RequiredKeys<T>` and `NullableKeys<T>` as intermediate type parameters:
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```typescript
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type ObjectResult<
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T extends ObjectProperties,
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R = RequiredKeys<T>, // ← Intermediate type parameter
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N = NullableKeys<T>, // ← Intermediate type parameter
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> = {
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type: "object";
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properties: {...};
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} & ([R] extends [never] ? {} : { required: UnionToTuple<R> })
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& ([N] extends [never] ? {} : { nullable: UnionToTuple<N> });
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```
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While the conditional checks prevented calling `UnionToTuple` when keys were `never`, TypeScript still had to instantiate the intermediate type parameters `R` and `N`, adding overhead.
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## What We Tried
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### Attempt 1: Remove Intermediate Type Parameters ✅ SUCCESS
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**Change:** Inline the `RequiredKeys<T>` and `NullableKeys<T>` calls directly into the conditional checks, removing the intermediate type parameter assignments.
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```typescript
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type ObjectResult<T extends ObjectProperties> = {
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type: "object";
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properties: {...};
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} & ([RequiredKeys<T>] extends [never]
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? {}
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: { required: UnionToTuple<RequiredKeys<T>> })
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& ([NullableKeys<T>] extends [never]
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? {}
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: { nullable: UnionToTuple<NullableKeys<T>> });
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```
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**Results:**
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- Simple object: 275 → **244 instantiations** (31 saved, ~11% improvement)
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- Complex nested: 542 → **507 instantiations** (35 saved, ~6% improvement)
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**Why it worked:** Removing intermediate type parameter assignments reduced the number of type instantiations. TypeScript now evaluates the key extraction inline within conditionals, which is more efficient than creating separate type aliases.
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### Attempt 2: Extract Helper Types ❌ FAILED
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**Change:** Created `AddRequiredField` and `AddNullableField` helper types to encapsulate the conditional logic:
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```typescript
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type AddRequiredField<R> = [R] extends [never]
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? {}
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: { required: UnionToTuple<R> };
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+
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type AddNullableField<N> = [N] extends [never]
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? {}
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: { nullable: UnionToTuple<N> };
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type ObjectResult<T extends ObjectProperties> = {
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type: "object";
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properties: {...};
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} & AddRequiredField<RequiredKeys<T>>
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& AddNullableField<NullableKeys<T>>;
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```
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**Results:**
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- Simple object: 244 → **263 instantiations** (19 worse, regressed)
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- Complex nested: 507 → **506 instantiations** (1 better, negligible)
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**Why it failed:** The helper types added additional type instantiation overhead that outweighed any benefits from code organization. Each helper type invocation created extra work for TypeScript's type checker.
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**Action taken:** Reverted to Attempt 1.
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## Final Results
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**Benchmark after this optimization:**
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- Simple object: **244 instantiations** (down from 275, saved 31)
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- Complex nested: **507 instantiations** (down from 542, saved 35)
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**Total progress from original todo.md baseline:**
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- Simple object: **578 → 244** (334 saved, 57.8% improvement) ✅ **GOAL MET** (target: 200-250)
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- Complex nested: **971 → 507** (464 saved, 47.8% improvement) ⚠️ Still above 400 target
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## Files Modified
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- `src/lib.ts`:
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- `ObjectResult<T>` type (lines 212-225)
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- `ParamsResult<T>` type (lines 237-245)
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## Validation
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- ✅ All 172 tests passing (`pnpm test`)
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- ✅ Type checking passes (`pnpm tsc`)
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- ✅ No runtime behavior changes (types erase at runtime)
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- ✅ IDE autocomplete still works with clean type display
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## Key Learnings
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1. **Intermediate type parameters have a cost**: Even when they're just aliases, TypeScript must instantiate them.
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2. **Inline conditionals can be more efficient**: Computing values inline within conditional types can reduce instantiation count compared to pre-computing and storing in type parameters.
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3. **Helper types aren't always helpful**: While helper types improve code organization, they can add overhead. Always benchmark after introducing abstractions.
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4. **Small changes add up**: A 31-instantiation reduction (11%) might seem modest, but combined with other optimizations, we achieved a 57.8% total improvement.
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---
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## Further Optimization Attempts (Post-Initial Success)
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### Attempt 3: Reduce InferObject Intersections (4 → 2) ❌ FAILED
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**Change:** Attempted to reduce the number of intersected mapped types in `InferObject` from 4 to 2 by combining key categories:
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```typescript
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type InferObject<...> = Prettify<
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T extends { properties: any }
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? {
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// All REQUIRED keys (with and without nullable)
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-readonly [K in keyof Props as K extends Required & string ? K : never]-?:
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K extends NullableAndRequired
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? InferType<Props[K]> | null
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: InferType<Props[K]>;
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} & {
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// All OPTIONAL keys (normal and nullable-only)
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-readonly [K in keyof Props as K extends Exclude<keyof Props & string, Required> ? K : never]?:
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K extends Nullable
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? InferType<Props[K]> | null
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: InferType<Props[K]>;
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}
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: {}
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>;
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```
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**Results:**
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- Simple object: **244 instantiations** (unchanged)
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- Complex nested: **507 instantiations** (unchanged)
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**Why it failed:**
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- The number of intersections wasn't the bottleneck
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- TypeScript still evaluates the same number of conditional checks
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- Property ordering changed (required first, then optional), breaking snapshot tests
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- No performance benefit to justify the breaking change
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**Action taken:** Reverted.
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### Attempt 4: Inline Type Parameters in InferObject ❌ FAILED
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**Change:** Removed all intermediate type parameters from `InferObject`, similar to what worked for `ObjectResult`:
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```typescript
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type InferObject<T> = Prettify<
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T extends { properties: infer P }
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? {
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-readonly [K in "properties" extends keyof T
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? Exclude<keyof T["properties"], (GetRequired<T> & string) | (GetNullable<T> & string)> & string
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: never]?: InferType<P[K & keyof P]>;
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} & {
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-readonly [K in Exclude<GetRequired<T> & string, ...>]-?: InferType<P[K & keyof P]>;
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} & ...
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: {}
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>;
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```
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**Results:**
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- Simple object: **244 instantiations** (unchanged)
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- Complex nested: **507 instantiations** (unchanged)
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**Why it failed:**
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- Unlike `ObjectResult` (which is only evaluated at definition time), `InferObject` is called recursively during type inference
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- The intermediate type parameters are likely cached/memoized by TypeScript during recursive evaluation
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- Inlining forces re-computation of the same values multiple times in each mapped type key
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- Tests passed but no performance improvement
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**Action taken:** Reverted.
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## Updated Key Learnings
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5. **Context matters for optimizations**: What works in one context (removing intermediate params in `ObjectResult`) may not work in another (`InferObject`). The recursive nature of type inference behaves differently than one-time type construction.
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6. **Intersection count isn't always the bottleneck**: Reducing from 4 to 2 intersections had zero impact, suggesting the real cost is elsewhere (likely `Prettify` at every nesting level or the recursive `InferType` calls).
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7. **TypeScript may optimize intermediate parameters**: In recursive scenarios, intermediate type parameters might be cached, making inlining counterproductive.
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### Attempt 5: Reorder InferType Dispatch Chain ❌ FAILED
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**Change:** Reordered the `InferType` conditional chain to prioritize the most commonly used types:
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**New order:**
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1. object (most common container)
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2. string (most common primitive)
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3. ref (common for schema references)
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4. array (common for collections)
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5. union (common for polymorphic types)
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6. integer, boolean (other common primitives)
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7. record, params, null, token, unknown, bytes, cid-link, blob (less common)
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**Previous order:**
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1. record, object, array, params, union, token, ref, unknown, null, boolean, integer, string, bytes, cid-link, blob
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```typescript
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type InferType<T> = T extends { type: "object" }
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? InferObject<T>
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: T extends { type: "string" }
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? string
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: T extends { type: "ref" }
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? InferRef<T>
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: T extends { type: "array" }
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? InferArray<T>
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// ... rest of the chain
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```
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**Results:**
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- Simple object: **244 instantiations** (unchanged)
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- Complex nested: **507 instantiations** (unchanged)
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**Why it failed:**
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- TypeScript's type checker likely doesn't evaluate conditional chains linearly
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- The order of conditionals has no impact on performance
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- TypeScript may cache or optimize type instantiations internally regardless of order
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- Tests pass, proving functional correctness, but zero performance benefit
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**Action taken:** Kept the new order (it's more readable with common types first), but no performance gain.
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## Next Potential Optimizations to Try
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1. **Optimize `Prettify` itself** - Since it's called at every nesting level, making it more efficient could have cascading benefits
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2. **Combine `GetRequired` and `GetNullable`** - Extract both in a single pass to reduce type instantiations
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3. **Cache commonly used helper types** - Though previous attempts suggest this might not help
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4. **Reduce Prettify calls** - Only call Prettify at the outermost level, not at every nesting
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package.json
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package.json
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src/infer.ts
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src/infer.ts
···
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import { Prettify } from "./type-utils.ts";
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/* eslint-disable @typescript-eslint/no-empty-object-type */
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type InferType<T> = T extends { type: "record" }
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? InferRecord<T>
···
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type InferToken<T> = T extends { enum: readonly (infer U)[] } ? U : string;
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type GetRequired<T> = T extends { required: readonly (infer R)[] } ? R : never;
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type GetNullable<T> = T extends { nullable: readonly (infer N)[] } ? N : never;
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export type GetRequired<T> = T extends { required: readonly (infer R)[] }
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? R
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: never;
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export type GetNullable<T> = T extends { nullable: readonly (infer N)[] }
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? N
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: never;
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type InferObject<
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T,
···
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: unknown
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: unknown;
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-
type InferParams<T> = T extends { properties: infer P }
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? InferObject<P>
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: never;
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type InferParams<T> = InferObject<T>;
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type InferRecord<T> = T extends { record: infer R }
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? R extends { type: "object" }
···
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: unknown
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: unknown;
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-
type Prettify<T> = {
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[K in keyof T]: T[K];
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} & {};
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-
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type InferDefs<T extends Record<string, unknown>> = Prettify<{
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type InferDefs<T extends Record<string, unknown>> = {
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-readonly [K in keyof T]: InferType<T[K]>;
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}>;
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};
100
100
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export type InferNS<T extends { id: string; defs: Record<string, unknown> }> =
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InferDefs<T["defs"]>;
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export type Infer<T extends { id: string; defs: Record<string, unknown> }> =
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Prettify<InferDefs<T["defs"]>>;
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-30
src/lib.ts
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-30
src/lib.ts
···
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// deno-lint-ignore-file ban-types
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3
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import type { InferNS } from "./infer.ts";
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/* eslint-disable @typescript-eslint/no-empty-object-type */
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import type { Infer } from "./infer.ts";
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import type { Prettify, UnionToTuple } from "./type-utils.ts";
4
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/** @see https://atproto.com/specs/lexicon#overview-of-types */
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type LexiconType =
···
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* Map of property names to their lexicon item definitions.
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192
* @see https://atproto.com/specs/lexicon#object
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*/
194
-
type ObjectProperties = Record<string, LexiconItem>;
194
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type ObjectProperties = Record<
195
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string,
196
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{
197
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type: LexiconType;
198
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}
199
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>;
200
+
201
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type RequiredKeys<T> = {
202
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[K in keyof T]: T[K] extends { required: true } ? K : never;
203
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}[keyof T];
204
+
205
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type NullableKeys<T> = {
206
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[K in keyof T]: T[K] extends { nullable: true } ? K : never;
207
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}[keyof T];
195
208
196
209
/**
197
210
* Resulting object schema with required and nullable fields extracted.
198
211
* @see https://atproto.com/specs/lexicon#object
199
212
*/
200
-
interface ObjectResult<T extends ObjectProperties> {
213
+
type ObjectResult<T extends ObjectProperties> = {
201
214
type: "object";
202
215
/** Property definitions */
203
-
properties: T;
204
-
/** List of required property names */
205
-
required?: string[];
206
-
/** List of nullable property names */
207
-
nullable?: string[];
208
-
}
216
+
properties: {
217
+
[K in keyof T]: T[K] extends { type: "object" }
218
+
? T[K]
219
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: Omit<T[K], "required" | "nullable">;
220
+
};
221
+
} & ([RequiredKeys<T>] extends [never]
222
+
? {}
223
+
: { required: UnionToTuple<RequiredKeys<T>> }) &
224
+
([NullableKeys<T>] extends [never]
225
+
? {}
226
+
: { nullable: UnionToTuple<NullableKeys<T>> });
209
227
210
228
/**
211
229
* Map of parameter names to their lexicon item definitions.
···
217
235
* Resulting params schema with required fields extracted.
218
236
* @see https://atproto.com/specs/lexicon#params
219
237
*/
220
-
interface ParamsResult<T extends ParamsProperties> {
238
+
type ParamsResult<T extends ParamsProperties> = {
221
239
type: "params";
222
240
/** Parameter definitions */
223
-
properties: T;
224
-
/** List of required parameter names */
225
-
required?: string[];
226
-
}
241
+
properties: {
242
+
[K in keyof T]: Omit<T[K], "required" | "nullable">;
243
+
};
244
+
} & ([RequiredKeys<T>] extends [never]
245
+
? {}
246
+
: { required: UnionToTuple<RequiredKeys<T>> });
227
247
228
248
/**
229
249
* HTTP request or response body schema.
···
309
329
310
330
class Namespace<T extends LexiconNamespace> {
311
331
public json: T;
312
-
public infer: InferNS<T> = null as unknown as InferNS<T>;
332
+
public infer: Infer<T> = null as unknown as Infer<T>;
313
333
314
334
constructor(json: T) {
315
335
this.json = json;
···
409
429
* Creates an array type with item schema and length constraints.
410
430
* @see https://atproto.com/specs/lexicon#array
411
431
*/
412
-
array<Items extends LexiconItem, Options extends ArrayOptions>(
432
+
array<Items extends { type: LexiconType }, Options extends ArrayOptions>(
413
433
items: Items,
414
434
options?: Options,
415
435
): Options & { type: "array"; items: Items } {
···
470
490
* Creates an object type with defined properties.
471
491
* @see https://atproto.com/specs/lexicon#object
472
492
*/
473
-
object<T extends ObjectProperties>(options: T): ObjectResult<T> {
493
+
object<T extends ObjectProperties>(options: T): Prettify<ObjectResult<T>> {
474
494
const required = Object.keys(options).filter(
475
-
(key) => options[key].required,
495
+
(key) => "required" in options[key] && options[key].required,
476
496
);
477
497
const nullable = Object.keys(options).filter(
478
-
(key) => options[key].nullable,
498
+
(key) => "nullable" in options[key] && options[key].nullable,
479
499
);
480
-
const result: ObjectResult<T> = {
500
+
const result: Record<string, unknown> = {
481
501
type: "object",
482
502
properties: options,
483
503
};
···
487
507
if (nullable.length > 0) {
488
508
result.nullable = nullable;
489
509
}
490
-
return result;
510
+
return result as ObjectResult<T>;
491
511
},
492
512
/**
493
513
* Creates a params type for query string parameters.
···
495
515
*/
496
516
params<Properties extends ParamsProperties>(
497
517
properties: Properties,
498
-
): ParamsResult<Properties> {
518
+
): Prettify<ParamsResult<Properties>> {
499
519
const required = Object.keys(properties).filter(
500
520
(key) => properties[key].required,
501
521
);
502
-
const result: {
503
-
type: "params";
504
-
properties: Properties;
505
-
required?: string[];
506
-
} = {
522
+
const result: Record<string, unknown> = {
507
523
type: "params",
508
524
properties,
509
525
};
510
526
if (required.length > 0) {
511
527
result.required = required;
512
528
}
513
-
return result;
529
+
return result as ParamsResult<Properties>;
514
530
},
515
531
/**
516
532
* Creates a query endpoint definition (HTTP GET).
+19
src/type-utils.ts
+19
src/type-utils.ts
···
1
+
/**
2
+
* Converts a string union type to a tuple type
3
+
* @example
4
+
* type Colors = "red" | "green" | "blue";
5
+
* type ColorTuple = UnionToTuple<Colors>; // ["red", "green", "blue"]
6
+
*/
7
+
export type UnionToTuple<T> = (
8
+
(T extends unknown ? (x: () => T) => void : never) extends (
9
+
x: infer I,
10
+
) => void
11
+
? I
12
+
: never
13
+
) extends () => infer R
14
+
? [...UnionToTuple<Exclude<T, R>>, R]
15
+
: [];
16
+
17
+
export type Prettify<T> = {
18
+
[K in keyof T]: T[K];
19
+
} & {};
+2
-4
tests/infer.bench.ts
+2
-4
tests/infer.bench.ts
···
8
8
name: lx.string({ required: true }),
9
9
}),
10
10
});
11
-
12
11
return schema.infer;
13
-
}).types([62, "instantiations"]);
12
+
}).types([244, "instantiations"]);
14
13
15
14
bench("InferNS with complex nested structure", () => {
16
15
const schema = lx.namespace("test.complex", {
···
32
31
author: lx.ref("test.complex#user", { required: true }),
33
32
}),
34
33
});
35
-
36
34
return schema.infer;
37
-
}).types([124, "instantiations"]);
35
+
}).types([507, "instantiations"]);
+713
-8
tests/infer.test.ts
+713
-8
tests/infer.test.ts
···
1
1
import { test } from "vitest";
2
2
import { attest } from "@ark/attest";
3
-
import type { InferNS } from "../src/infer.ts";
4
3
import { lx } from "../src/lib.ts";
5
4
6
5
test("InferNS produces expected type shape", () => {
···
19
18
// Type snapshot - this captures how types appear on hover
20
19
attest(exampleLexicon.infer).type.toString.snap(`{
21
20
main: {
22
-
createdAt?: string | undefined
23
21
tags?: string[] | undefined
24
-
text?: string | undefined
25
22
likes?: number | undefined
23
+
createdAt: string
24
+
text: string
26
25
}
27
26
}`);
28
27
});
···
36
35
});
37
36
38
37
attest(schema.infer).type.toString.snap(`{
39
-
main: {
40
-
required?: string | undefined
41
-
optional?: string | undefined
42
-
}
38
+
main: { optional?: string | undefined; required: string }
43
39
}`);
44
40
});
45
41
···
51
47
});
52
48
53
49
attest(schema.infer).type.toString.snap(
54
-
"{ main: { nullable?: string | undefined } }",
50
+
"{ main: { nullable: string | null } }",
51
+
);
52
+
});
53
+
54
+
// ============================================================================
55
+
// PRIMITIVE TYPES TESTS
56
+
// ============================================================================
57
+
58
+
test("InferType handles string primitive", () => {
59
+
const namespace = lx.namespace("test.string", {
60
+
main: lx.object({
61
+
simpleString: lx.string(),
62
+
}),
63
+
});
64
+
65
+
attest(namespace.infer).type.toString.snap(
66
+
"{ main: { simpleString?: string | undefined } }",
67
+
);
68
+
});
69
+
70
+
test("InferType handles integer primitive", () => {
71
+
const namespace = lx.namespace("test.integer", {
72
+
main: lx.object({
73
+
count: lx.integer(),
74
+
age: lx.integer({ minimum: 0, maximum: 120 }),
75
+
}),
76
+
});
77
+
78
+
attest(namespace.infer).type.toString.snap(`{
79
+
main: {
80
+
count?: number | undefined
81
+
age?: number | undefined
82
+
}
83
+
}`);
84
+
});
85
+
86
+
test("InferType handles boolean primitive", () => {
87
+
const namespace = lx.namespace("test.boolean", {
88
+
main: lx.object({
89
+
isActive: lx.boolean(),
90
+
hasAccess: lx.boolean({ required: true }),
91
+
}),
92
+
});
93
+
94
+
attest(namespace.infer).type.toString.snap(`{
95
+
main: {
96
+
isActive?: boolean | undefined
97
+
hasAccess: boolean
98
+
}
99
+
}`);
100
+
});
101
+
102
+
test("InferType handles null primitive", () => {
103
+
const namespace = lx.namespace("test.null", {
104
+
main: lx.object({
105
+
nullValue: lx.null(),
106
+
}),
107
+
});
108
+
109
+
attest(namespace.infer).type.toString.snap(
110
+
"{ main: { nullValue?: null | undefined } }",
111
+
);
112
+
});
113
+
114
+
test("InferType handles unknown primitive", () => {
115
+
const namespace = lx.namespace("test.unknown", {
116
+
main: lx.object({
117
+
metadata: lx.unknown(),
118
+
}),
119
+
});
120
+
121
+
attest(namespace.infer).type.toString.snap(
122
+
"{ main: { metadata?: unknown } }",
123
+
);
124
+
});
125
+
126
+
test("InferType handles bytes primitive", () => {
127
+
const namespace = lx.namespace("test.bytes", {
128
+
main: lx.object({
129
+
data: lx.bytes(),
130
+
}),
131
+
});
132
+
133
+
attest(namespace.infer).type.toString.snap(`{
134
+
main: { data?: Uint8Array<ArrayBufferLike> | undefined }
135
+
}`);
136
+
});
137
+
138
+
test("InferType handles blob primitive", () => {
139
+
const namespace = lx.namespace("test.blob", {
140
+
main: lx.object({
141
+
image: lx.blob({ accept: ["image/png", "image/jpeg"] }),
142
+
}),
143
+
});
144
+
145
+
attest(namespace.infer).type.toString.snap(
146
+
"{ main: { image?: Blob | undefined } }",
147
+
);
148
+
});
149
+
150
+
// ============================================================================
151
+
// TOKEN TYPE TESTS
152
+
// ============================================================================
153
+
154
+
test("InferToken handles basic token without enum", () => {
155
+
const namespace = lx.namespace("test.token", {
156
+
main: lx.object({
157
+
symbol: lx.token("A symbolic value"),
158
+
}),
159
+
});
160
+
161
+
attest(namespace.infer).type.toString.snap(
162
+
"{ main: { symbol?: string | undefined } }",
163
+
);
164
+
});
165
+
166
+
// ============================================================================
167
+
// ARRAY TYPE TESTS
168
+
// ============================================================================
169
+
170
+
test("InferArray handles string arrays", () => {
171
+
const namespace = lx.namespace("test.array.string", {
172
+
main: lx.object({
173
+
tags: lx.array(lx.string()),
174
+
}),
175
+
});
176
+
177
+
attest(namespace.infer).type.toString.snap(
178
+
"{ main: { tags?: string[] | undefined } }",
179
+
);
180
+
});
181
+
182
+
test("InferArray handles integer arrays", () => {
183
+
const namespace = lx.namespace("test.array.integer", {
184
+
main: lx.object({
185
+
scores: lx.array(lx.integer(), { minLength: 1, maxLength: 10 }),
186
+
}),
187
+
});
188
+
189
+
attest(namespace.infer).type.toString.snap(
190
+
"{ main: { scores?: number[] | undefined } }",
191
+
);
192
+
});
193
+
194
+
test("InferArray handles boolean arrays", () => {
195
+
const namespace = lx.namespace("test.array.boolean", {
196
+
main: lx.object({
197
+
flags: lx.array(lx.boolean()),
198
+
}),
199
+
});
200
+
201
+
attest(namespace.infer).type.toString.snap(
202
+
"{ main: { flags?: boolean[] | undefined } }",
203
+
);
204
+
});
205
+
206
+
test("InferArray handles unknown arrays", () => {
207
+
const namespace = lx.namespace("test.array.unknown", {
208
+
main: lx.object({
209
+
items: lx.array(lx.unknown()),
210
+
}),
211
+
});
212
+
213
+
attest(namespace.infer).type.toString.snap(
214
+
"{ main: { items?: unknown[] | undefined } }",
215
+
);
216
+
});
217
+
218
+
// ============================================================================
219
+
// OBJECT PROPERTY COMBINATIONS
220
+
// ============================================================================
221
+
222
+
test("InferObject handles mixed optional and required fields", () => {
223
+
const namespace = lx.namespace("test.mixed", {
224
+
main: lx.object({
225
+
id: lx.string({ required: true }),
226
+
name: lx.string({ required: true }),
227
+
email: lx.string(),
228
+
age: lx.integer(),
229
+
}),
230
+
});
231
+
232
+
attest(namespace.infer).type.toString.snap(`{
233
+
main: {
234
+
age?: number | undefined
235
+
email?: string | undefined
236
+
id: string
237
+
name: string
238
+
}
239
+
}`);
240
+
});
241
+
242
+
test("InferObject handles all optional fields", () => {
243
+
const namespace = lx.namespace("test.allOptional", {
244
+
main: lx.object({
245
+
field1: lx.string(),
246
+
field2: lx.integer(),
247
+
field3: lx.boolean(),
248
+
}),
249
+
});
250
+
251
+
attest(namespace.infer).type.toString.snap(`{
252
+
main: {
253
+
field1?: string | undefined
254
+
field2?: number | undefined
255
+
field3?: boolean | undefined
256
+
}
257
+
}`);
258
+
});
259
+
260
+
test("InferObject handles all required fields", () => {
261
+
const namespace = lx.namespace("test.allRequired", {
262
+
main: lx.object({
263
+
field1: lx.string({ required: true }),
264
+
field2: lx.integer({ required: true }),
265
+
field3: lx.boolean({ required: true }),
266
+
}),
267
+
});
268
+
269
+
attest(namespace.infer).type.toString.snap(`{
270
+
main: { field1: string; field2: number; field3: boolean }
271
+
}`);
272
+
});
273
+
274
+
// ============================================================================
275
+
// NULLABLE FIELDS TESTS
276
+
// ============================================================================
277
+
278
+
test("InferObject handles nullable optional field", () => {
279
+
const namespace = lx.namespace("test.nullableOptional", {
280
+
main: lx.object({
281
+
description: lx.string({ nullable: true }),
282
+
}),
283
+
});
284
+
285
+
attest(namespace.infer).type.toString.snap(`{
286
+
main: { description?: string | null | undefined }
287
+
}`);
288
+
});
289
+
290
+
test("InferObject handles multiple nullable fields", () => {
291
+
const namespace = lx.namespace("test.multipleNullable", {
292
+
main: lx.object({
293
+
field1: lx.string({ nullable: true }),
294
+
field2: lx.integer({ nullable: true }),
295
+
field3: lx.boolean({ nullable: true }),
296
+
}),
297
+
});
298
+
299
+
attest(namespace.infer).type.toString.snap(`{
300
+
main: {
301
+
field1?: string | null | undefined
302
+
field2?: number | null | undefined
303
+
field3?: boolean | null | undefined
304
+
}
305
+
}`);
306
+
});
307
+
308
+
test("InferObject handles nullable and required field", () => {
309
+
const namespace = lx.namespace("test.nullableRequired", {
310
+
main: lx.object({
311
+
value: lx.string({ nullable: true, required: true }),
312
+
}),
313
+
});
314
+
315
+
attest(namespace.infer).type.toString.snap(
316
+
"{ main: { value: string | null } }",
317
+
);
318
+
});
319
+
320
+
test("InferObject handles mixed nullable, required, and optional", () => {
321
+
const namespace = lx.namespace("test.mixedNullable", {
322
+
main: lx.object({
323
+
requiredNullable: lx.string({ required: true, nullable: true }),
324
+
optionalNullable: lx.string({ nullable: true }),
325
+
required: lx.string({ required: true }),
326
+
optional: lx.string(),
327
+
}),
328
+
});
329
+
330
+
attest(namespace.infer).type.toString.snap(`{
331
+
main: {
332
+
optional?: string | undefined
333
+
required: string
334
+
optionalNullable?: string | null | undefined
335
+
requiredNullable: string | null
336
+
}
337
+
}`);
338
+
});
339
+
340
+
// ============================================================================
341
+
// REF TYPE TESTS
342
+
// ============================================================================
343
+
344
+
test("InferRef handles basic reference", () => {
345
+
const namespace = lx.namespace("test.ref", {
346
+
main: lx.object({
347
+
post: lx.ref("com.example.post"),
348
+
}),
349
+
});
350
+
351
+
attest(namespace.infer).type.toString.snap(`{
352
+
main: {
353
+
post?:
354
+
| {
355
+
[key: string]: unknown
356
+
$type: "com.example.post"
357
+
}
358
+
| undefined
359
+
}
360
+
}`);
361
+
});
362
+
363
+
test("InferRef handles required reference", () => {
364
+
const namespace = lx.namespace("test.refRequired", {
365
+
main: lx.object({
366
+
author: lx.ref("com.example.user", { required: true }),
367
+
}),
368
+
});
369
+
370
+
attest(namespace.infer).type.toString.snap(`{
371
+
main: {
372
+
author?:
373
+
| {
374
+
[key: string]: unknown
375
+
$type: "com.example.user"
376
+
}
377
+
| undefined
378
+
}
379
+
}`);
380
+
});
381
+
382
+
test("InferRef handles nullable reference", () => {
383
+
const namespace = lx.namespace("test.refNullable", {
384
+
main: lx.object({
385
+
parent: lx.ref("com.example.node", { nullable: true }),
386
+
}),
387
+
});
388
+
389
+
attest(namespace.infer).type.toString.snap(`{
390
+
main: {
391
+
parent?:
392
+
| {
393
+
[key: string]: unknown
394
+
$type: "com.example.node"
395
+
}
396
+
| undefined
397
+
}
398
+
}`);
399
+
});
400
+
401
+
// ============================================================================
402
+
// UNION TYPE TESTS
403
+
// ============================================================================
404
+
405
+
test("InferUnion handles basic union", () => {
406
+
const namespace = lx.namespace("test.union", {
407
+
main: lx.object({
408
+
content: lx.union(["com.example.text", "com.example.image"]),
409
+
}),
410
+
});
411
+
412
+
attest(namespace.infer).type.toString.snap(`{
413
+
main: {
414
+
content?:
415
+
| {
416
+
[key: string]: unknown
417
+
$type: "com.example.text"
418
+
}
419
+
| {
420
+
[key: string]: unknown
421
+
$type: "com.example.image"
422
+
}
423
+
| undefined
424
+
}
425
+
}`);
426
+
});
427
+
428
+
test("InferUnion handles required union", () => {
429
+
const namespace = lx.namespace("test.unionRequired", {
430
+
main: lx.object({
431
+
media: lx.union(["com.example.video", "com.example.audio"], {
432
+
required: true,
433
+
}),
434
+
}),
435
+
});
436
+
437
+
attest(namespace.infer).type.toString.snap(`{
438
+
main: {
439
+
media:
440
+
| {
441
+
[key: string]: unknown
442
+
$type: "com.example.video"
443
+
}
444
+
| {
445
+
[key: string]: unknown
446
+
$type: "com.example.audio"
447
+
}
448
+
}
449
+
}`);
450
+
});
451
+
452
+
test("InferUnion handles union with many types", () => {
453
+
const namespace = lx.namespace("test.unionMultiple", {
454
+
main: lx.object({
455
+
attachment: lx.union([
456
+
"com.example.image",
457
+
"com.example.video",
458
+
"com.example.audio",
459
+
"com.example.document",
460
+
]),
461
+
}),
462
+
});
463
+
464
+
attest(namespace.infer).type.toString.snap(`{
465
+
main: {
466
+
attachment?:
467
+
| {
468
+
[key: string]: unknown
469
+
$type: "com.example.image"
470
+
}
471
+
| {
472
+
[key: string]: unknown
473
+
$type: "com.example.video"
474
+
}
475
+
| {
476
+
[key: string]: unknown
477
+
$type: "com.example.audio"
478
+
}
479
+
| {
480
+
[key: string]: unknown
481
+
$type: "com.example.document"
482
+
}
483
+
| undefined
484
+
}
485
+
}`);
486
+
});
487
+
488
+
// ============================================================================
489
+
// PARAMS TYPE TESTS
490
+
// ============================================================================
491
+
492
+
test("InferParams handles basic params", () => {
493
+
const namespace = lx.namespace("test.params", {
494
+
main: lx.params({
495
+
limit: lx.integer(),
496
+
offset: lx.integer(),
497
+
}),
498
+
});
499
+
500
+
attest(namespace.infer).type.toString.snap(`{
501
+
main: {
502
+
limit?: number | undefined
503
+
offset?: number | undefined
504
+
}
505
+
}`);
506
+
});
507
+
508
+
test("InferParams handles required params", () => {
509
+
const namespace = lx.namespace("test.paramsRequired", {
510
+
main: lx.params({
511
+
query: lx.string({ required: true }),
512
+
limit: lx.integer(),
513
+
}),
514
+
});
515
+
516
+
attest(namespace.infer).type.toString.snap(`{
517
+
main: { limit?: number | undefined; query: string }
518
+
}`);
519
+
});
520
+
521
+
// ============================================================================
522
+
// RECORD TYPE TESTS
523
+
// ============================================================================
524
+
525
+
test("InferRecord handles record with object schema", () => {
526
+
const namespace = lx.namespace("test.record", {
527
+
main: lx.record({
528
+
key: "tid",
529
+
record: lx.object({
530
+
title: lx.string({ required: true }),
531
+
content: lx.string({ required: true }),
532
+
published: lx.boolean(),
533
+
}),
534
+
}),
535
+
});
536
+
537
+
attest(namespace.infer).type.toString.snap(`{
538
+
main: {
539
+
published?: boolean | undefined
540
+
content: string
541
+
title: string
542
+
}
543
+
}`);
544
+
});
545
+
546
+
// ============================================================================
547
+
// NESTED OBJECTS TESTS
548
+
// ============================================================================
549
+
550
+
test("InferObject handles nested objects", () => {
551
+
const namespace = lx.namespace("test.nested", {
552
+
main: lx.object({
553
+
user: lx.object({
554
+
name: lx.string({ required: true }),
555
+
email: lx.string({ required: true }),
556
+
}),
557
+
}),
558
+
});
559
+
560
+
attest(namespace.infer).type.toString.snap(`{
561
+
main: {
562
+
user?: { name: string; email: string } | undefined
563
+
}
564
+
}`);
565
+
});
566
+
567
+
test("InferObject handles deeply nested objects", () => {
568
+
const namespace = lx.namespace("test.deepNested", {
569
+
main: lx.object({
570
+
data: lx.object({
571
+
user: lx.object({
572
+
profile: lx.object({
573
+
name: lx.string({ required: true }),
574
+
}),
575
+
}),
576
+
}),
577
+
}),
578
+
});
579
+
580
+
attest(namespace.infer).type.toString.snap(`{
581
+
main: {
582
+
data?:
583
+
| {
584
+
user?:
585
+
| { profile?: { name: string } | undefined }
586
+
| undefined
587
+
}
588
+
| undefined
589
+
}
590
+
}`);
591
+
});
592
+
593
+
// ============================================================================
594
+
// NESTED ARRAYS TESTS
595
+
// ============================================================================
596
+
597
+
test("InferArray handles arrays of objects", () => {
598
+
const namespace = lx.namespace("test.arrayOfObjects", {
599
+
main: lx.object({
600
+
users: lx.array(
601
+
lx.object({
602
+
id: lx.string({ required: true }),
603
+
name: lx.string({ required: true }),
604
+
}),
605
+
),
606
+
}),
607
+
});
608
+
609
+
attest(namespace.infer).type.toString.snap(`{
610
+
main: {
611
+
users?: { id: string; name: string }[] | undefined
612
+
}
613
+
}`);
614
+
});
615
+
616
+
test("InferArray handles arrays of arrays", () => {
617
+
const schema = lx.object({
618
+
matrix: lx.array(lx.array(lx.integer())),
619
+
});
620
+
621
+
const namespace = lx.namespace("test.nestedArrays", {
622
+
main: schema,
623
+
});
624
+
625
+
attest(namespace.infer).type.toString.snap(
626
+
"{ main: { matrix?: number[][] | undefined } }",
55
627
);
56
628
});
629
+
630
+
test("InferArray handles arrays of refs", () => {
631
+
const namespace = lx.namespace("test.arrayOfRefs", {
632
+
main: lx.object({
633
+
followers: lx.array(lx.ref("com.example.user")),
634
+
}),
635
+
});
636
+
637
+
attest(namespace.infer).type.toString.snap(`{
638
+
main: {
639
+
followers?:
640
+
| {
641
+
[key: string]: unknown
642
+
$type: "com.example.user"
643
+
}[]
644
+
| undefined
645
+
}
646
+
}`);
647
+
});
648
+
649
+
// ============================================================================
650
+
// COMPLEX NESTED STRUCTURES
651
+
// ============================================================================
652
+
653
+
test("InferObject handles complex nested structure", () => {
654
+
const namespace = lx.namespace("test.complex", {
655
+
main: lx.object({
656
+
id: lx.string({ required: true }),
657
+
author: lx.object({
658
+
did: lx.string({ required: true, format: "did" }),
659
+
handle: lx.string({ required: true, format: "handle" }),
660
+
avatar: lx.string(),
661
+
}),
662
+
content: lx.union(["com.example.text", "com.example.image"]),
663
+
tags: lx.array(lx.string(), { maxLength: 10 }),
664
+
metadata: lx.object({
665
+
views: lx.integer(),
666
+
likes: lx.integer(),
667
+
shares: lx.integer(),
668
+
}),
669
+
}),
670
+
});
671
+
672
+
attest(namespace.infer).type.toString.snap(`{
673
+
main: {
674
+
tags?: string[] | undefined
675
+
content?:
676
+
| {
677
+
[key: string]: unknown
678
+
$type: "com.example.text"
679
+
}
680
+
| {
681
+
[key: string]: unknown
682
+
$type: "com.example.image"
683
+
}
684
+
| undefined
685
+
author?:
686
+
| {
687
+
avatar?: string | undefined
688
+
did: string
689
+
handle: string
690
+
}
691
+
| undefined
692
+
metadata?:
693
+
| {
694
+
likes?: number | undefined
695
+
views?: number | undefined
696
+
shares?: number | undefined
697
+
}
698
+
| undefined
699
+
id: string
700
+
}
701
+
}`);
702
+
});
703
+
704
+
// ============================================================================
705
+
// MULTIPLE DEFS IN NAMESPACE
706
+
// ============================================================================
707
+
708
+
test("InferNS handles multiple defs in namespace", () => {
709
+
const namespace = lx.namespace("com.example.app", {
710
+
user: lx.object({
711
+
name: lx.string({ required: true }),
712
+
email: lx.string({ required: true }),
713
+
}),
714
+
post: lx.object({
715
+
title: lx.string({ required: true }),
716
+
content: lx.string({ required: true }),
717
+
}),
718
+
comment: lx.object({
719
+
text: lx.string({ required: true }),
720
+
author: lx.ref("com.example.user"),
721
+
}),
722
+
});
723
+
724
+
attest(namespace.infer).type.toString.snap(`{
725
+
user: { name: string; email: string }
726
+
post: { content: string; title: string }
727
+
comment: {
728
+
author?:
729
+
| {
730
+
[key: string]: unknown
731
+
$type: "com.example.user"
732
+
}
733
+
| undefined
734
+
text: string
735
+
}
736
+
}`);
737
+
});
738
+
739
+
test("InferNS handles namespace with record and object defs", () => {
740
+
const namespace = lx.namespace("com.example.blog", {
741
+
main: lx.record({
742
+
key: "tid",
743
+
record: lx.object({
744
+
title: lx.string({ required: true }),
745
+
body: lx.string({ required: true }),
746
+
}),
747
+
}),
748
+
metadata: lx.object({
749
+
category: lx.string(),
750
+
tags: lx.array(lx.string()),
751
+
}),
752
+
});
753
+
754
+
attest(namespace.infer).type.toString.snap(`{
755
+
main: { title: string; body: string }
756
+
metadata: {
757
+
tags?: string[] | undefined
758
+
category?: string | undefined
759
+
}
760
+
}`);
761
+
});
-58
todo.md
-58
todo.md
···
1
-
# typed-lexicon - Development TODO
2
-
3
-
## Project Goal
4
-
5
-
Build a toolkit for writing ATProto lexicon JSON schemas in TypeScript that:
6
-
7
-
- Removes boilerplate and improves ergonomics
8
-
- Provides type hints for
9
-
[atproto type parameters](https://atproto.com/specs/lexicon#overview-of-types)
10
-
- Infers TypeScript type definitions for data shapes to avoid duplication and
11
-
skew
12
-
- Includes methods and a CLI for generating JSON
13
-
14
-
## Files to Read
15
-
16
-
When working on this project, always reference:
17
-
18
-
1. **`lib.ts`** - Main implementation file with all `lx.*` methods
19
-
2. **`tests/primitives.test.ts`** - Tests for all implemented types
20
-
3. **`tests/base-case.test.ts`** - Example usage test
21
-
4. **`README.md`** - Project direction and example usage
22
-
23
-
## Essential Resources
24
-
25
-
When implementing new lexicon types, fetch from:
26
-
27
-
- **Main spec**: https://atproto.com/specs/lexicon#overview-of-types
28
-
- **Data model**: https://atproto.com/specs/data-model
29
-
- **ATProto lexicon examples**:
30
-
- https://github.com/bluesky-social/atproto/blob/main/lexicons/app/bsky/actor/defs.json
31
-
(for `ref` examples)
32
-
- https://github.com/bluesky-social/atproto/blob/main/lexicons/app/bsky/feed/defs.json
33
-
(for `token` examples)
34
-
35
-
## Implementation Status
36
-
37
-
- ✅ Initial implementation of field types returning json definitions
38
-
- ✅ Bsky actor and feed test files created and passing
39
-
(`tests/bsky-actor.test.ts` and `tests/bsky-feed.test.ts`)
40
-
41
-
## Todo
42
-
43
-
### CLI for JSON Emission
44
-
45
-
1. **Design CLI** - Determine command structure, flags, and output strategy
46
-
2. **Create JSON emission logic** - Traverse lexicon objects and serialize to
47
-
formatted JSON
48
-
3. **Add file I/O** - Read TypeScript lexicon files, write JSON output files
49
-
4. **Write CLI documentation** - Usage examples, flag reference, common
50
-
workflows
51
-
52
-
### Type Inference System
53
-
54
-
Infer TypeScript types from lexicon definitions
55
-
56
-
### `validate()`
57
-
58
-
validate any lexicon schema json at runtime