/** * @fileoverview Tests for no-unused-expressions rule. * @author Michael Ficarra */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const rule = require("../../rules/no-unused-expressions"), RuleTester = require("../RuleTester"); //------------------------------------------------------------------------------ // Tests //------------------------------------------------------------------------------ const ruleTester = new RuleTester(); ruleTester.run("no-unused-expressions", rule, { valid: [ // Original test cases. "function f(){}", "a = b", "new a", "{}", "f(); g()", "i++", "a()", { code: "a && a()", options: [{ allowShortCircuit: true }] }, { code: "a() || (b = c)", options: [{ allowShortCircuit: true }] }, { code: "a ? b() : c()", options: [{ allowTernary: true }] }, { code: "a ? b() || (c = d) : e()", options: [{ allowShortCircuit: true, allowTernary: true }] }, "delete foo.bar", "void new C", "\"use strict\";", "\"directive one\"; \"directive two\"; f();", "function foo() {\"use strict\"; return true; }", { code: "var foo = () => {\"use strict\"; return true; }", parserOptions: { ecmaVersion: 6 } }, "function foo() {\"directive one\"; \"directive two\"; f(); }", "function foo() { var foo = \"use strict\"; return true; }", { code: "function* foo(){ yield 0; }", parserOptions: { ecmaVersion: 6 } }, { code: "async function foo() { await 5; }", parserOptions: { ecmaVersion: 8 } }, { code: "async function foo() { await foo.bar; }", parserOptions: { ecmaVersion: 8 } }, { code: "async function foo() { bar && await baz; }", options: [{ allowShortCircuit: true }], parserOptions: { ecmaVersion: 8 } }, { code: "async function foo() { foo ? await bar : await baz; }", options: [{ allowTernary: true }], parserOptions: { ecmaVersion: 8 } }, { code: "tag`tagged template literal`", options: [{ allowTaggedTemplates: true }], parserOptions: { ecmaVersion: 6 } }, { code: "shouldNotBeAffectedByAllowTemplateTagsOption()", options: [{ allowTaggedTemplates: true }], parserOptions: { ecmaVersion: 6 } }, // Babel-specific test cases. "let a = do { if (foo) { foo.bar; } }", "let a = do { foo; }", "let a = do { let b = 2; foo; }", "let a = do { (foo + 1); }", "let a = do { if (foo) { if (foo.bar) { foo.bar; } } }", "let a = do { if (foo) { if (foo.bar) { foo.bar; } else if (foo.baz) { foo.baz; } } }", "foo.bar?.();", ], invalid: [ { code: "0", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "f(), 0", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "{0}", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "[]", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a && b();", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a() || false", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a || (b = c)", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a ? b() || (c = d) : e", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "`untagged template literal`", parserOptions: { ecmaVersion: 6 }, errors: ["Expected an assignment or function call and instead saw an expression."] }, { code: "tag`tagged template literal`", parserOptions: { ecmaVersion: 6 }, errors: ["Expected an assignment or function call and instead saw an expression."] }, { code: "a && b()", options: [{ allowTernary: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a ? b() : c()", options: [{ allowShortCircuit: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a || b", options: [{ allowShortCircuit: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a() && b", options: [{ allowShortCircuit: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a ? b : 0", options: [{ allowTernary: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "a ? b : c()", options: [{ allowTernary: true }], errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "foo.bar;", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "!a", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "+a", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "\"directive one\"; f(); \"directive two\";", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "function foo() {\"directive one\"; f(); \"directive two\"; }", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "if (0) { \"not a directive\"; f(); }", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "function foo() { var foo = true; \"use strict\"; }", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "var foo = () => { var foo = true; \"use strict\"; }", parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "`untagged template literal`", options: [{ allowTaggedTemplates: true }], parserOptions: { ecmaVersion: 6 }, errors: ["Expected an assignment or function call and instead saw an expression."] }, { code: "`untagged template literal`", options: [{ allowTaggedTemplates: false }], parserOptions: { ecmaVersion: 6 }, errors: ["Expected an assignment or function call and instead saw an expression."] }, { code: "tag`tagged template literal`", options: [{ allowTaggedTemplates: false }], parserOptions: { ecmaVersion: 6 }, errors: ["Expected an assignment or function call and instead saw an expression."] }, // Babel-specific test cases. { code: "let a = do { foo; let b = 2; }", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, { code: "let a = do { if (foo) { foo.bar } else { a; bar.foo } }", errors: [{ message: "Expected an assignment or function call and instead saw an expression.", type: "ExpressionStatement" }] }, ] });