Lints and suggestions for the Nix programming language
remove isNull deprecation lint (#86)
see https://github.com/NixOS/nix/pull/9645
-82
-6
bin/tests/data/deprecated_is_null.nix
-6
bin/tests/data/deprecated_is_null.nix
-1
bin/tests/main.rs
-1
bin/tests/main.rs
-13
bin/tests/snapshots/main__deprecated_is_null.snap
-13
bin/tests/snapshots/main__deprecated_is_null.snap
···
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---
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source: bin/tests/main.rs
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expression: "&out"
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---
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[W13] Warning: Found usage of deprecated builtin isNull
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╭─[data/deprecated_is_null.nix:4:4]
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│
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4 │ if isNull e
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· ────┬───
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· ╰───── isNull is deprecated, check equality with null instead
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───╯
13
-
-1
lib/src/lints.rs
-1
lib/src/lints.rs
-60
lib/src/lints/deprecated_is_null.rs
-60
lib/src/lints/deprecated_is_null.rs
···
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use crate::{make, session::SessionInfo, Metadata, Report, Rule, Suggestion};
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-
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use if_chain::if_chain;
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use macros::lint;
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use rnix::{
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types::{Apply, Ident, TokenWrapper, TypedNode},
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NodeOrToken, SyntaxElement, SyntaxKind,
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};
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/// ## What it does
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/// Checks for usage of the `isNull` function.
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///
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/// ## Why is this bad?
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/// `isNull` is deprecated.
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///
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/// ## Example
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///
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/// Instead of `isNull` for `null` checks,
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///
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/// ```nix
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/// isNull e
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/// ```
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///
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/// use the equality operator:
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///
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/// ```nix
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/// e == null
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/// ```
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#[lint(
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name = "deprecated_is_null",
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note = "Found usage of deprecated builtin isNull",
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code = 13,
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match_with = SyntaxKind::NODE_APPLY
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)]
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struct DeprecatedIsNull;
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impl Rule for DeprecatedIsNull {
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fn validate(&self, node: &SyntaxElement, _sess: &SessionInfo) -> Option<Report> {
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if_chain! {
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if let NodeOrToken::Node(node) = node;
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if let Some(apply) = Apply::cast(node.clone());
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if let Some(ident) = Ident::cast(apply.lambda()?);
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if ident.as_str() == "isNull";
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if let Some(value) = apply.value();
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then {
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let null = make::ident("null");
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let binop = make::binary(&value, "==", null.node());
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let parenthesized = make::parenthesize(binop.node());
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let at = node.text_range();
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let replacement = parenthesized.node().clone();
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let message = "`isNull` is deprecated, check equality with `null` instead";
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Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
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} else {
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None
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}
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}
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}
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}