Allow unknown in 'no-object-literal-type-assertion' rule. (palantir#4362

) * Fix palantir#4355 Allow unknown in 'no-object-literal-type-assertion' rule. * Allow unknown in TS 2.0 as well. * Allow unknown type assertion
joekaiser · Dec 12, 2018 · e8a620d · e8a620d
1 parent 5d9f1bd
commit e8a620d
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diff --git a/src/rules/noObjectLiteralTypeAssertionRule.ts b/src/rules/noObjectLiteralTypeAssertionRule.ts
@@ -30,7 +30,7 @@ export class Rule extends Lint.Rules.AbstractRule {
         ruleName: "no-object-literal-type-assertion",
         description: Lint.Utils.dedent`
             Forbids an object literal to appear in a type assertion expression.
-            Casting to \`any\` is still allowed.`,
+            Casting to \`any\` or to \`unknown\` is still allowed.`,
         rationale: Lint.Utils.dedent`
             Always prefer \`const x: T = { ... };\` to \`const x = { ... } as T;\`.
             The type assertion in the latter case is either unnecessary or hides an error.
@@ -58,6 +58,10 @@ function walk(ctx: Lint.WalkContext<void>): void {
         if (
             isAssertionExpression(node) &&
             node.type.kind !== ts.SyntaxKind.AnyKeyword &&
+            // Compare with UnknownKeyword if using TS 3.0 or above
+            (!!(ts.SyntaxKind as any).UnknownKeyword ?
+             (node.type.kind !== (ts.SyntaxKind as any).UnknownKeyword) :
+             node.type.getText(ctx.sourceFile) !== "unknown") &&
             isObjectLiteralExpression(
                 isParenthesizedExpression(node.expression)
                     ? node.expression.expression

diff --git a/test/rules/no-object-literal-type-assertion/test.ts.lint b/test/rules/no-object-literal-type-assertion/test.ts.lint
@@ -12,4 +12,8 @@ x as T;
 {} as any;
 <any> {};
 
+// Allow cast to 'unknown'
+{} as unknown;
+<unknown> {};
+
 [0]: Type assertion on object literals is forbidden, use a type annotation instead.