.changeset/big-keys-play.md (1)

5-5: Polish the changeset (tense split, final full stop, canonical docs URL, add example).

Bring it in line with our changeset conventions: past tense for the action, present tense for current behaviour, sentences ending with a full stop, and include a representative example. Also swap the Japanese docs URL for the canonical one.

-Fixed [#7381](https://github.com/biomejs/biome/issues/7381), now the [`useOptionalChain`](https://biomejs.dev/ja/linter/rules/use-optional-chain/) rule recognizes optional chaining using Yoda expressions (e.g., `undefined !== foo && foo.bar`)
+Fixed [#7381](https://github.com/biomejs/biome/issues/7381).
+The [`useOptionalChain`](https://biomejs.dev/linter/rules/use-optional-chain/) rule now recognises optional chaining when written as Yoda expressions.
+
+#### Example
+```js
+// Before
+undefined !== foo && foo.bar
+// After
+foo?.bar
+```

crates/biome_js_analyze/tests/specs/complexity/useOptionalChain/yoda_expressions_logicalAndCases5.js (1)

56-66: Add ‘void 0’ Yoda variants to exercise undefined aliasing.

Many codebases still use void 0 for undefined. Adding a couple of lines ensures the extractor treats it equivalently.

 // chained calls
 undefined != foo && undefined != foo.bar && undefined != foo.bar.baz && foo.bar.baz.buzz()
 undefined != foo && undefined != foo.bar && undefined != foo.bar.baz && undefined != foo.bar.baz.buzz && foo.bar.baz.buzz()
 undefined != foo.bar && undefined != foo.bar.baz && undefined != foo.bar.baz.buzz && foo.bar.baz.buzz()
+
+// 'void 0' variants (alias of undefined)
+void 0 != foo && foo.bar
+void 0 != foo.bar && foo.bar.baz
+void 0 != foo && foo()

crates/biome_js_analyze/tests/specs/complexity/useOptionalChain/yoda_expressions_logicalAndCases4.js (1)

48-55: Consider a couple of parenthesised Yoda forms and ‘void 0’ strict variants.

Parentheses and void 0 are cheap extra edges that have bitten normalisers before.

 undefined !== foo && undefined !== foo.bar && undefined !== foo.bar.baz && foo.bar.baz.buzz
 undefined !== foo.bar && undefined !== foo.bar.baz && foo.bar.baz.buzz
+
+// Parenthesised expressions
+(null !== (foo)) && (foo).bar
+(undefined !== (foo?.bar)) && (foo?.bar).baz
+
+// 'void 0' strict variants
+void 0 !== foo && foo.bar
+void 0 !== foo.bar && foo.bar.baz

crates/biome_js_analyze/tests/specs/complexity/useOptionalChain/yoda_expressions_logicalAndCases6.jsx (1)

21-27: Private fields outside a declaring class may trigger early errors—please confirm parser mode.

Access like foo.#bar is an early error unless the private names are declared in the containing class. If our test harness disables early errors, we're fine; otherwise, consider wrapping these in a minimal class to keep fixtures parseable.

Happy to propose a wrapped variant if needed.

crates/biome_js_analyze/tests/specs/complexity/useOptionalChain/yoda_expressions_validCases.ts (3)

36-39: Remove duplicated valid case.

foo["some long"] && foo["some long string"].baz; appears twice (Lines 36 and 38). Drop one to keep the fixture lean.

Apply:

-foo["some long"] && foo["some long string"].baz;
 foo[`some long`] && foo[`some long string`].baz;
-foo["some long"] && foo["some long string"].baz;

---

46-47: Track or enable the commented-out case.

The FIXME for (new foo() || {}).bar suggests an expected no-diagnostic. Either enable it (if now supported) or link a tracking issue in a comment for future work.

Happy to raise a follow-up issue and add a focused test once confirmed.

---

1-1: Test filename convention.

Our snapshots typically use files prefixed with valid* / invalid*. Consider renaming this to start with valid (e.g., valid.yoda_expressions.ts) for consistency with the harness.

crates/biome_js_analyze/tests/specs/complexity/useOptionalChain/yoda_expressions_logicalAndCases3.js (1)

26-62: Add non‑strict and undefined Yoda coverage.

Great breadth. To fully exercise the extractor, add a couple of != cases and undefined !== … variants, e.g.:

• undefined != foo && foo.bar
• undefined !== foo.bar && foo.bar.baz

crates/biome_js_syntax/src/expr_ext.rs (1)

345-369: Recognise void … as undefined (and consider globalThis.undefined).

is_nullish only checks literal null and identifier undefined. Many codebases use void 0 (or void any) as undefined. Optionally recognise it; likewise globalThis.undefined/window.undefined if you wish to be generous.

Apply minimal support for void:

 fn is_nullish(expression: &AnyJsExpression) -> bool {
-    expression
-        .as_static_value()
-        .is_some_and(|x| x.is_null_or_undefined())
+    expression
+        .as_static_value()
+        .is_some_and(|x| x.is_null_or_undefined())
+        || matches!(
+            expression,
+            AnyJsExpression::JsUnaryExpression(u)
+                if u.operator().is_ok_and(|op| matches!(op, JsUnaryOperator::Void))
+        )
 }

If you also want globalThis.undefined:

- fn is_nullish(expression: &AnyJsExpression) -> bool {
+ fn is_nullish(expression: &AnyJsExpression) -> bool {
     // existing checks …
+    || crate::global_identifier(expression)
+        .is_some_and(|(_, name)| matches!(name, StaticValue::String(tok) if tok.text_trimmed() == "undefined"))
 }

crates/biome_js_analyze/src/lint/complexity/use_optional_chain.rs (1)

564-567: Minor readability tweak for nested ??.

ok()?? is concise but slightly opaque. Consider expanding for clarity.

-AnyJsExpression::JsBinaryExpression(expression) => {
-    expression.extract_optional_chain_like().ok()??
-}
+AnyJsExpression::JsBinaryExpression(expression) => {
+    match expression.extract_optional_chain_like() {
+        Ok(Some(expr)) => expr,
+        _ => return None,
+    }
+}

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Learnt from: CR
PR: biomejs/biome#0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2025-08-17T08:56:30.831Z
Learning: Applies to crates/biome_analyze/crates/**/lib/src/**/nursery/**/*.rs : Avoid `unwrap`/`expect`; use `?`, `ok()?`, and combinators (`map`, `and_then`, `filter`) to handle `Result`/`Option` when navigating the CST

Learnt from: CR
PR: biomejs/biome#0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2025-08-17T08:56:30.831Z
Learning: Applies to crates/biome_analyze/crates/**/tests/specs/**/{invalid*,valid*}.{js,jsx,ts,tsx,css,graphql,jsonc} : Place snapshot test cases under `tests/specs/<group>/<ruleName>/` using files prefixed with `invalid` and `valid`