Add exception for generators in "return-undefined" rule (palantir#4370)

* Add exception for generators in "return-undefined" rule * Fix linter error
ovr · Dec 12, 2018 · a21ba7d · a21ba7d
1 parent 2729aac
commit a21ba7d
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diff --git a/src/rules/returnUndefinedRule.ts b/src/rules/returnUndefinedRule.ts
@@ -117,6 +117,11 @@ function getReturnKind(node: FunctionLike, checker: ts.TypeChecker): ReturnKind
             return ReturnKind.Value;
     }
 
+    // Handle generator functions/methods:
+    if (node.asteriskToken !== undefined) {
+        return ReturnKind.Void;
+    }
+
     const contextual =
         isFunctionExpressionLike(node) && node.type === undefined
             ? tryGetReturnType(checker.getContextualType(node), checker)

diff --git a/test/rules/return-undefined/test.ts.lint b/test/rules/return-undefined/test.ts.lint
@@ -78,5 +78,19 @@ test(async () => {
          ~~~~~~~~~~~~~~~~~ [VOID]
 });
 
+
+function * generator(returnNothing: boolean) {
+    if (returnNothing) return;
+    yield 1;
+    return yield * [2, 3];
+}
+
+class ClassWithGeneratorMethod {
+    * generatorMethod(returnNothing: boolean) {
+        if (returnNothing) return;
+        yield 1;
+    }
+}
+
 [VOID]: `void` function should use `return;`, not `return undefined;`.
 [UNDEFINED]: Value-returning function should use `return undefined;`, not just `return;`.