fix(compiler-cli): error in unused standalone imports diagnostic (#59064)

crisbeto · alxhub · commit cd764a311520 · 2024-12-05T16:14:02.000-08:00
Fixes a null pointer error in the unused standalone imports diagnostic. It was caused by an inconsistency in TypeScript's built-in types. Fixes #58872. PR Close #59064
diff --git a/packages/compiler-cli/src/ngtsc/validation/src/rules/unused_standalone_imports_rule.ts b/packages/compiler-cli/src/ngtsc/validation/src/rules/unused_standalone_imports_rule.ts
@@ -172,7 +172,10 @@ export class UnusedStandaloneImportsRule implements SourceFileValidatorRule {
       if (ts.isVariableStatement(current)) {
         return !!current.modifiers?.some((m) => m.kind === ts.SyntaxKind.ExportKeyword);
       }
-      current = current.parent;
+
+      // `Node.parent` can be undefined, but the TS types don't reflect it.
+      // Coerce to null so the value is consitent with the type.
+      current = current.parent ?? null;
     }
 
     // Otherwise the reference likely comes from an imported

Original file line number	Diff line number	Diff line change
`@@ -172,7 +172,10 @@ export class UnusedStandaloneImportsRule implements SourceFileValidatorRule {`
`172`	`172`	`if (ts.isVariableStatement(current)) {`
`173`	`173`	`return !!current.modifiers?.some((m) => m.kind === ts.SyntaxKind.ExportKeyword);`
`174`	`174`	`}`
`175`		`- current = current.parent;`
	`175`	`+`
	`176`	+ // `Node.parent` can be undefined, but the TS types don't reflect it.
	`177`	`+ // Coerce to null so the value is consitent with the type.`
	`178`	`+ current = current.parent ?? null;`
`176`	`179`	`}`
`177`	`180`
`178`	`181`	`// Otherwise the reference likely comes from an imported`