An experimental TypeSpec syntax for Lexicon
feat: add @lexConst and @record decorators for advanced lexicon patterns
Implemented support for two new lexicon patterns:
1. @lexConst decorator for boolean constant values
- Maps to lexicon's "const" field
- Used for discriminated unions (e.g., notFound: true, blocked: true)
2. @record decorator for repository record types
- Wraps models in lexicon "record" type structure
- Supports key types (tid, literal:self, any)
- Example: app.bsky.graph.follow (social follow relationship)
Key fixes:
- Prevent duplicate processing when model named "Main" has @lexiconMain
- Export new decorators from index.ts
- Handle description placement for record-wrapped definitions
- Use namespace name directly for Main models with @lexiconMain
Tests: 23/23 passing
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
+509
-9
+14
packages/emitter/lib/decorators.tsp
+14
packages/emitter/lib/decorators.tsp
···
47
47
* Specifies maximum size in bytes for a blob field.
48
48
*/
49
49
extern dec blobMaxSize(target: unknown, size: valueof int32);
50
+
51
+
/**
52
+
* Marks a boolean field as having a constant value.
53
+
* Maps to lexicon's "const" field.
54
+
*/
55
+
extern dec lexConst(target: unknown, value: valueof boolean);
56
+
57
+
/**
58
+
* Marks a model as a record type with a specific key type.
59
+
* Maps to lexicon's "record" type.
60
+
*
61
+
* @param key - The key type for the record (e.g., "tid", "literal:self", "any")
62
+
*/
63
+
extern dec record(target: unknown, key: valueof string);
+26
packages/emitter/src/decorators.ts
+26
packages/emitter/src/decorators.ts
···
7
7
const lexiconMainKey = Symbol("lexiconMain");
8
8
const blobAcceptKey = Symbol("blobAccept");
9
9
const blobMaxSizeKey = Symbol("blobMaxSize");
10
+
const constKey = Symbol("const");
11
+
const recordKey = Symbol("record");
10
12
11
13
/**
12
14
* @lexFormat decorator for lexicon-specific string formats
···
120
122
export function getBlobMaxSize(program: Program, target: Type): number | undefined {
121
123
return program.stateMap(blobMaxSizeKey).get(target);
122
124
}
125
+
126
+
/**
127
+
* @lexConst decorator for constant boolean values
128
+
*/
129
+
export function $lexConst(context: DecoratorContext, target: Type, value: Type) {
130
+
const boolValue = (value as any).kind === "Boolean" ? (value as any).value : value;
131
+
context.program.stateMap(constKey).set(target, Boolean(boolValue));
132
+
}
133
+
134
+
export function getLexConst(program: Program, target: Type): boolean | undefined {
135
+
return program.stateMap(constKey).get(target);
136
+
}
137
+
138
+
/**
139
+
* @record decorator for record type lexicons
140
+
*/
141
+
export function $record(context: DecoratorContext, target: Type, key: Type) {
142
+
const keyValue = (key as any).kind === "String" ? (key as any).value : key;
143
+
context.program.stateMap(recordKey).set(target, keyValue);
144
+
}
145
+
146
+
export function getRecordKey(program: Program, target: Type): string | undefined {
147
+
return program.stateMap(recordKey).get(target);
148
+
}
+39
-8
packages/emitter/src/emitter.ts
+39
-8
packages/emitter/src/emitter.ts
···
32
32
isLexiconMain,
33
33
getBlobAccept,
34
34
getBlobMaxSize,
35
+
getLexConst,
36
+
getRecordKey,
35
37
} from "./decorators.js";
36
38
37
39
export interface EmitterOptions {
···
79
81
const standaloneModels = models.filter((m) =>
80
82
isLexiconMain(this.program, m),
81
83
);
82
-
const mainModel = models.find((m) => m.name === "Main");
84
+
const mainModel = models.find(
85
+
(m) => m.name === "Main" && !isLexiconMain(this.program, m),
86
+
);
83
87
const otherModels = models.filter(
84
88
(m) => !isLexiconMain(this.program, m) && m.name !== "Main",
85
89
);
86
90
87
91
// Case 1: Models marked with @lexiconMain -> standalone lexicon with ONLY main
88
92
for (const model of standaloneModels) {
89
-
const lexiconId =
90
-
fullName +
91
-
"." +
92
-
model.name.charAt(0).toLowerCase() +
93
-
model.name.slice(1);
93
+
// If model is named "Main", use namespace directly, otherwise append model name
94
+
const lexiconId = model.name === "Main"
95
+
? fullName
96
+
: fullName +
97
+
"." +
98
+
model.name.charAt(0).toLowerCase() +
99
+
model.name.slice(1);
94
100
this.currentLexiconId = lexiconId;
95
101
96
102
const modelDef = this.modelToLexiconObject(model, false);
97
103
const description =
98
104
getDoc(this.program, ns) || getDoc(this.program, model);
99
105
106
+
// Check if this is a record type
107
+
const recordKey = getRecordKey(this.program, model);
108
+
let mainDef: any = modelDef;
109
+
110
+
if (recordKey) {
111
+
// Wrap the object in a record structure
112
+
mainDef = {
113
+
type: "record",
114
+
key: recordKey,
115
+
record: modelDef,
116
+
};
117
+
118
+
// Add description to record def if it exists
119
+
if (description) {
120
+
mainDef.description = description;
121
+
}
122
+
}
123
+
100
124
const lexicon: LexiconDocument = {
101
125
lexicon: 1,
102
126
id: lexiconId,
103
127
defs: {
104
-
main: modelDef,
128
+
main: mainDef,
105
129
},
106
130
};
107
131
108
-
if (description) {
132
+
// Only add description to lexicon if not a record type (records have it on main def)
133
+
if (description && !recordKey) {
109
134
lexicon.description = description;
110
135
}
111
136
···
494
519
const knownValues = getLexKnownValues(this.program, prop);
495
520
if (knownValues) {
496
521
primitive.knownValues = knownValues;
522
+
}
523
+
524
+
// Check for const value on boolean properties
525
+
const constValue = getLexConst(this.program, prop);
526
+
if (constValue !== undefined && primitive.type === "boolean") {
527
+
(primitive as any).const = constValue;
497
528
}
498
529
}
499
530
+2
packages/emitter/src/index.ts
+2
packages/emitter/src/index.ts
+14
packages/emitter/test/scenarios/app-bsky-graph-follow/input/main.tsp
+14
packages/emitter/test/scenarios/app-bsky-graph-follow/input/main.tsp
···
1
+
import "@typlex/emitter";
2
+
3
+
namespace app.bsky.graph.follow {
4
+
@lexiconMain
5
+
@record("tid")
6
+
@doc("Record declaring a social 'follow' relationship of another account. Duplicate follows will be ignored by the AppView.")
7
+
model Main {
8
+
@lexFormat("did")
9
+
subject: string;
10
+
11
+
@lexFormat("datetime")
12
+
createdAt: string;
13
+
}
14
+
}
+19
packages/emitter/test/scenarios/app-bsky-graph-follow/output/app/bsky/graph/follow.json
+19
packages/emitter/test/scenarios/app-bsky-graph-follow/output/app/bsky/graph/follow.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.bsky.graph.follow",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"description": "Record declaring a social 'follow' relationship of another account. Duplicate follows will be ignored by the AppView.",
8
+
"key": "tid",
9
+
"record": {
10
+
"type": "object",
11
+
"required": ["subject", "createdAt"],
12
+
"properties": {
13
+
"subject": { "type": "string", "format": "did" },
14
+
"createdAt": { "type": "string", "format": "datetime" }
15
+
}
16
+
}
17
+
}
18
+
}
19
+
}
+1
-1
packages/example/.atprotorc.yaml
+1
-1
packages/example/.atprotorc.yaml
+34
packages/example/lexicon/app/example/entity.json
+34
packages/example/lexicon/app/example/entity.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.entity",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"start": {
12
+
"type": "integer",
13
+
"description": "Start index in text"
14
+
},
15
+
"end": {
16
+
"type": "integer",
17
+
"description": "End index in text"
18
+
},
19
+
"value": {
20
+
"type": "string",
21
+
"description": "Entity value (handle, URL, or tag)"
22
+
}
23
+
},
24
+
"required": [
25
+
"start",
26
+
"end",
27
+
"type",
28
+
"value"
29
+
]
30
+
},
31
+
"description": "Entity mentioned or linked in a post"
32
+
}
33
+
}
34
+
}
+29
packages/example/lexicon/app/example/follow.json
+29
packages/example/lexicon/app/example/follow.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.follow",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"subject": {
12
+
"type": "string",
13
+
"description": "DID of the account being followed"
14
+
},
15
+
"createdAt": {
16
+
"type": "string",
17
+
"format": "datetime",
18
+
"description": "When the follow was created"
19
+
}
20
+
},
21
+
"required": [
22
+
"subject",
23
+
"createdAt"
24
+
]
25
+
},
26
+
"description": "A follow relationship"
27
+
}
28
+
}
29
+
}
+43
packages/example/lexicon/app/example/like.json
+43
packages/example/lexicon/app/example/like.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.like",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"subject": {
12
+
"type": "object",
13
+
"properties": {
14
+
"uri": {
15
+
"type": "string",
16
+
"description": "AT URI of the post"
17
+
},
18
+
"cid": {
19
+
"type": "string",
20
+
"description": "CID of the post"
21
+
}
22
+
},
23
+
"description": "The post being liked",
24
+
"required": [
25
+
"uri",
26
+
"cid"
27
+
]
28
+
},
29
+
"createdAt": {
30
+
"type": "string",
31
+
"format": "datetime",
32
+
"description": "When the like was created"
33
+
}
34
+
},
35
+
"required": [
36
+
"subject",
37
+
"createdAt"
38
+
]
39
+
},
40
+
"description": "A like on a post"
41
+
}
42
+
}
43
+
}
+110
packages/example/lexicon/app/example/post.json
+110
packages/example/lexicon/app/example/post.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.post",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"text": {
12
+
"type": "string",
13
+
"description": "Post text content"
14
+
},
15
+
"createdAt": {
16
+
"type": "string",
17
+
"format": "datetime",
18
+
"description": "Creation timestamp"
19
+
},
20
+
"langs": {
21
+
"type": "array",
22
+
"items": {
23
+
"type": "string"
24
+
},
25
+
"description": "Languages the post is written in"
26
+
},
27
+
"entities": {
28
+
"type": "array",
29
+
"items": {
30
+
"type": "object",
31
+
"properties": {
32
+
"start": {
33
+
"type": "integer",
34
+
"description": "Start index in text"
35
+
},
36
+
"end": {
37
+
"type": "integer",
38
+
"description": "End index in text"
39
+
},
40
+
"value": {
41
+
"type": "string",
42
+
"description": "Entity value (handle, URL, or tag)"
43
+
}
44
+
},
45
+
"description": "Entity mentioned or linked in a post",
46
+
"required": [
47
+
"start",
48
+
"end",
49
+
"type",
50
+
"value"
51
+
]
52
+
},
53
+
"description": "Referenced entities in the post"
54
+
},
55
+
"reply": {
56
+
"type": "object",
57
+
"properties": {
58
+
"root": {
59
+
"type": "object",
60
+
"properties": {
61
+
"uri": {
62
+
"type": "string",
63
+
"description": "AT URI of the post"
64
+
},
65
+
"cid": {
66
+
"type": "string",
67
+
"description": "CID of the post"
68
+
}
69
+
},
70
+
"description": "Root post in thread",
71
+
"required": [
72
+
"uri",
73
+
"cid"
74
+
]
75
+
},
76
+
"parent": {
77
+
"type": "object",
78
+
"properties": {
79
+
"uri": {
80
+
"type": "string",
81
+
"description": "AT URI of the post"
82
+
},
83
+
"cid": {
84
+
"type": "string",
85
+
"description": "CID of the post"
86
+
}
87
+
},
88
+
"description": "Direct parent being replied to",
89
+
"required": [
90
+
"uri",
91
+
"cid"
92
+
]
93
+
}
94
+
},
95
+
"description": "Post the user is replying to",
96
+
"required": [
97
+
"root",
98
+
"parent"
99
+
]
100
+
}
101
+
},
102
+
"required": [
103
+
"text",
104
+
"createdAt"
105
+
]
106
+
},
107
+
"description": "A post in the feed"
108
+
}
109
+
}
110
+
}
+28
packages/example/lexicon/app/example/postRef.json
+28
packages/example/lexicon/app/example/postRef.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.postRef",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"uri": {
12
+
"type": "string",
13
+
"description": "AT URI of the post"
14
+
},
15
+
"cid": {
16
+
"type": "string",
17
+
"description": "CID of the post"
18
+
}
19
+
},
20
+
"required": [
21
+
"uri",
22
+
"cid"
23
+
]
24
+
},
25
+
"description": "Reference to a post"
26
+
}
27
+
}
28
+
}
+50
packages/example/lexicon/app/example/profile.json
+50
packages/example/lexicon/app/example/profile.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.profile",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"did": {
12
+
"type": "string",
13
+
"description": "Decentralized identifier"
14
+
},
15
+
"handle": {
16
+
"type": "string",
17
+
"description": "Handle identifier"
18
+
},
19
+
"displayName": {
20
+
"type": "string",
21
+
"description": "Display name shown in UI"
22
+
},
23
+
"description": {
24
+
"type": "string",
25
+
"description": "User biography"
26
+
},
27
+
"avatar": {
28
+
"type": "string",
29
+
"description": "Avatar image URL"
30
+
},
31
+
"banner": {
32
+
"type": "string",
33
+
"description": "Banner image URL"
34
+
},
35
+
"createdAt": {
36
+
"type": "string",
37
+
"format": "datetime",
38
+
"description": "When the profile was created"
39
+
}
40
+
},
41
+
"required": [
42
+
"did",
43
+
"handle",
44
+
"createdAt"
45
+
]
46
+
},
47
+
"description": "User profile information"
48
+
}
49
+
}
50
+
}
+56
packages/example/lexicon/app/example/replyRef.json
+56
packages/example/lexicon/app/example/replyRef.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.replyRef",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"root": {
12
+
"type": "object",
13
+
"properties": {
14
+
"uri": {
15
+
"type": "string",
16
+
"description": "AT URI of the post"
17
+
},
18
+
"cid": {
19
+
"type": "string",
20
+
"description": "CID of the post"
21
+
}
22
+
},
23
+
"description": "Root post in thread",
24
+
"required": [
25
+
"uri",
26
+
"cid"
27
+
]
28
+
},
29
+
"parent": {
30
+
"type": "object",
31
+
"properties": {
32
+
"uri": {
33
+
"type": "string",
34
+
"description": "AT URI of the post"
35
+
},
36
+
"cid": {
37
+
"type": "string",
38
+
"description": "CID of the post"
39
+
}
40
+
},
41
+
"description": "Direct parent being replied to",
42
+
"required": [
43
+
"uri",
44
+
"cid"
45
+
]
46
+
}
47
+
},
48
+
"required": [
49
+
"root",
50
+
"parent"
51
+
]
52
+
},
53
+
"description": "Reference to the post being replied to"
54
+
}
55
+
}
56
+
}
+43
packages/example/lexicon/app/example/repost.json
+43
packages/example/lexicon/app/example/repost.json
···
1
+
{
2
+
"lexicon": 1,
3
+
"id": "app.example.repost",
4
+
"defs": {
5
+
"main": {
6
+
"type": "record",
7
+
"key": "tid",
8
+
"record": {
9
+
"type": "object",
10
+
"properties": {
11
+
"subject": {
12
+
"type": "object",
13
+
"properties": {
14
+
"uri": {
15
+
"type": "string",
16
+
"description": "AT URI of the post"
17
+
},
18
+
"cid": {
19
+
"type": "string",
20
+
"description": "CID of the post"
21
+
}
22
+
},
23
+
"description": "The post being reposted",
24
+
"required": [
25
+
"uri",
26
+
"cid"
27
+
]
28
+
},
29
+
"createdAt": {
30
+
"type": "string",
31
+
"format": "datetime",
32
+
"description": "When the repost was created"
33
+
}
34
+
},
35
+
"required": [
36
+
"subject",
37
+
"createdAt"
38
+
]
39
+
},
40
+
"description": "A repost of another post"
41
+
}
42
+
}
43
+
}