ladybird/Libraries/LibJS/Tests/functions/function-strict-mode.js

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test("non strict-mode by default", () => {
  expect(isStrictMode()).toBeFalse();
});

test("use strict with double quotes", () => {
  "use strict";
  expect(isStrictMode()).toBeTrue();
});

test("use strict with single quotes", () => {
  'use strict';
  expect(isStrictMode()).toBeTrue();
});

test("use strict with backticks does not yield strict mode", () => {
  `use strict`;
  expect(isStrictMode()).toBeFalse();
});

test("use strict with single quotes after statement does not yield strict mode code", () => {
  ;'use strict';
  expect(isStrictMode()).toBeFalse();
});

test("use strict with double quotes after statement does not yield strict mode code", () => {
  ;"use strict";
  expect(isStrictMode()).toBeFalse();
});

test("strict mode propogates down the scope chain", () => {
  "use strict";
  expect(isStrictMode()).toBeTrue();
  (function() {
    expect(isStrictMode()).toBeTrue();
  })();
});

test("strict mode does not propogate up the scope chain", () => {
  expect(isStrictMode()).toBeFalse();
  (function() {
    "use strict";
    expect(isStrictMode()).toBeTrue();
  })();
  expect(isStrictMode()).toBeFalse();
});

test('only the string "use strict" yields strict mode code', () => {
  "use stric";
  expect(isStrictMode()).toBeFalse();
});