diff --git a/docs/ExpectAPI.md b/docs/ExpectAPI.md
index 06b4a9d643b5..d0ced25354bf 100644
--- a/docs/ExpectAPI.md
+++ b/docs/ExpectAPI.md
@@ -654,7 +654,7 @@ test('the house has my desired features', () => {
### `toHaveProperty(keyPath, value)`
-Use `.toHaveProperty` to check if property at provided reference `keyPath` exists for an object.
+Use `.toHaveProperty` to check if property at provided reference `keyPath` exists for an object.
For checking deeply nested properties in an object use [dot notation](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Property_accessors) for deep references.
Optionally, you can provide a value to check if it's strictly equal to the `value` present
@@ -666,17 +666,17 @@ to check for the existence and values of various properties in the object.
```js
// Object containing house features to be tested
const houseForSale = {
- bath: true,
- kitchen: {
- amenities: ['oven', 'stove', 'washer'],
- area: 20,
- wallColor: 'white'
- },
+ bath: true,
bedrooms: 4,
+ kitchen: {
+ amenities: ['oven', 'stove', 'washer'],
+ area: 20,
+ wallColor: 'white',
+ },
};
test('this house has my desired features', () => {
- // Simple Referencing
+ // Simple Referencing
expect(houseForSale).toHaveProperty('bath');
expect(houseForSale).toHaveProperty('bedrooms', 4);
@@ -684,7 +684,11 @@ test('this house has my desired features', () => {
// Deep referencing using dot notation
expect(houseForSale).toHaveProperty('kitchen.area', 20);
- expect(houseForSale).toHaveProperty('kitchen.amenities', ['oven', 'stove', 'washer']);
+ expect(houseForSale).toHaveProperty('kitchen.amenities', [
+ 'oven',
+ 'stove',
+ 'washer',
+ ]);
expect(hosueForSale).not.toHaveProperty('kitchen.open');
});
diff --git a/docs/SetupAndTeardown.md b/docs/SetupAndTeardown.md
index f31cfa4ee461..847b6aacab0f 100644
--- a/docs/SetupAndTeardown.md
+++ b/docs/SetupAndTeardown.md
@@ -93,11 +93,11 @@ describe('matching cities to foods', () => {
});
test('Vienna <3 sausage', () => {
- expect(isValidCityFoodPair('Vienna', 'Wiener Schnitzel'));
+ expect(isValidCityFoodPair('Vienna', 'Wiener Schnitzel')).toBe(true);
});
test('San Juan <3 plantains', () => {
- expect(isValidCityFoodPair('San Juan', 'Mofongo'));
+ expect(isValidCityFoodPair('San Juan', 'Mofongo')).toBe(true);
});
});
```
diff --git a/packages/eslint-config-fb-strict/index.js b/packages/eslint-config-fb-strict/index.js
index cd117af84654..bc27f4d89acb 100644
--- a/packages/eslint-config-fb-strict/index.js
+++ b/packages/eslint-config-fb-strict/index.js
@@ -41,6 +41,7 @@ module.exports = Object.assign({}, fbjsConfig, {
'flowtype/object-type-delimiter': [2, 'comma'],
'jest/no-focused-tests': [2],
'jest/no-identical-title': [2],
+ 'jest/valid-expect': [2],
'max-len': [2, {
'code': 80,
'ignorePattern': maxLenIgnorePattern,
diff --git a/packages/eslint-plugin-jest/README.md b/packages/eslint-plugin-jest/README.md
index 4477ff63e1e0..5e094766369b 100644
--- a/packages/eslint-plugin-jest/README.md
+++ b/packages/eslint-plugin-jest/README.md
@@ -31,6 +31,7 @@ Then configure the rules you want to use under the rules section.
"jest/no-disabled-tests": "warn",
"jest/no-focused-tests": "error",
"jest/no-identical-title": "error",
+ "jest/valid-expect": "error",
}
}
```
@@ -50,6 +51,7 @@ You can also whitelist the environment variables provided by Jest by doing:
- [no-disabled-tests](/packages/eslint-plugin-jest/docs/rules/no-disabled-tests.md) - disallow disabled tests.
- [no-focused-tests](/packages/eslint-plugin-jest/docs/rules/no-focused-tests.md) - disallow focused tests.
- [no-identical-title](/packages/eslint-plugin-jest/docs/rules/no-identical-title.md) - disallow identical titles.
+- [valid-expect](/packages/eslint-plugin-jest/docs/rules/valid-expect.md) - ensure expect is called correctly.
## Shareable configurations
@@ -72,6 +74,7 @@ The rules enabled in this configuration are:
- [jest/no-disabled-tests](/packages/eslint-plugin-jest/docs/rules/no-disabled-tests.md)
- [jest/no-focused-tests](/packages/eslint-plugin-jest/docs/rules/no-focused-tests.md)
- [jest/no-identical-title](/packages/eslint-plugin-jest/docs/rules/no-identical-title.md)
+- [jest/valid-expect](/packages/eslint-plugin-jest/docs/rules/valid-expect.md)
## Credit
diff --git a/packages/eslint-plugin-jest/docs/rules/valid-expect.md b/packages/eslint-plugin-jest/docs/rules/valid-expect.md
new file mode 100644
index 000000000000..8a3e10c4e79d
--- /dev/null
+++ b/packages/eslint-plugin-jest/docs/rules/valid-expect.md
@@ -0,0 +1,41 @@
+# Enforce valid `expect()` usage (valid-expect)
+
+Ensure `expect()` is called with a single argument and there is an actual expectation made.
+
+## Rule details
+
+This rule triggers a warning if `expect()` is called with more than one argument or without arguments.
+It would also issue a warning if there is nothing called on `expect()`, e.g.:
+
+```js
+expect();
+expect('something');
+```
+
+or when a matcher function was not called, e.g.:
+
+```js
+expect(true).toBeDefined
+```
+
+This rule is enabled by default.
+
+### Default configuration
+
+The following patterns are considered warnings:
+
+```js
+expect();
+expect().toEqual('something');
+expect('something', 'else');
+expect('something');
+expect(true).toBeDefined;
+```
+
+The following patterns are not warnings:
+
+```js
+expect('something').toEqual('something');
+expect([1, 2, 3]).toEqual([1, 2, 3]);
+expect(true).toBeDefined();
+```
diff --git a/packages/eslint-plugin-jest/src/index.js b/packages/eslint-plugin-jest/src/index.js
index ebb599cccfe9..7f1d5a456a57 100644
--- a/packages/eslint-plugin-jest/src/index.js
+++ b/packages/eslint-plugin-jest/src/index.js
@@ -17,6 +17,7 @@ module.exports = {
'jest/no-disabled-tests': 'warn',
'jest/no-focused-tests': 'error',
'jest/no-identical-title': 'error',
+ 'jest/valid-expect': 'error',
},
},
},
@@ -46,5 +47,6 @@ module.exports = {
'no-disabled-tests': require('./rules/no-disabled-tests'),
'no-focused-tests': require('./rules/no-focused-tests'),
'no-identical-title': require('./rules/no-identical-title'),
+ 'valid-expect': require('./rules/valid-expect'),
},
};
diff --git a/packages/eslint-plugin-jest/src/rules/__tests__/valid-expect-test.js b/packages/eslint-plugin-jest/src/rules/__tests__/valid-expect-test.js
new file mode 100644
index 000000000000..b8785bfbc18c
--- /dev/null
+++ b/packages/eslint-plugin-jest/src/rules/__tests__/valid-expect-test.js
@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ */
+
+/* eslint-disable sort-keys */
+
+'use strict';
+
+const RuleTester = require('eslint').RuleTester;
+const rules = require('../../').rules;
+
+const ruleTester = new RuleTester();
+
+ruleTester.run('valid-expect', rules['valid-expect'], {
+ valid: [
+ 'expect("something").toEqual("else");',
+ 'expect(true).toBeDefined();',
+ 'expect([1, 2, 3]).toEqual([1, 2, 3]);',
+ 'expect(undefined).not.toBeDefined();',
+ ],
+
+ invalid: [
+ {
+ code: 'expect().toBe(true);',
+ errors: [
+ {
+ message: 'No arguments were passed to expect().',
+ },
+ ],
+ },
+ {
+ code: 'expect().toEqual("something");',
+ errors: [
+ {
+ message: 'No arguments were passed to expect().',
+ },
+ ],
+ },
+ {
+ code: 'expect("something", "else").toEqual("something");',
+ errors: [
+ {
+ message: 'More than one argument was passed to expect().',
+ },
+ ],
+ },
+ {
+ code: 'expect("something");',
+ errors: [
+ {
+ message: 'No assertion was called on expect().',
+ },
+ ],
+ },
+ {
+ code: 'expect();',
+ errors: [
+ {
+ message: 'No arguments were passed to expect().',
+ },
+ {
+ message: 'No assertion was called on expect().',
+ },
+ ],
+ },
+ {
+ code: 'expect(true).toBeDefined;',
+ errors: [
+ {
+ message: '"toBeDefined" was not called.',
+ },
+ ],
+ },
+ ],
+});
diff --git a/packages/eslint-plugin-jest/src/rules/types.js b/packages/eslint-plugin-jest/src/rules/types.js
index 9bd936295768..90e1af71d1ad 100644
--- a/packages/eslint-plugin-jest/src/rules/types.js
+++ b/packages/eslint-plugin-jest/src/rules/types.js
@@ -8,31 +8,37 @@
* @flow
*/
-export type Identifier = {|
+type Node = MemberExpression | CallExpression;
+
+export type Identifier = {
type: 'Identifier',
name: string,
value: string,
-|};
+ parent: Node,
+};
-export type MemberExpression = {|
+export type MemberExpression = {
type: 'MemberExpression',
name: string,
expression: CallExpression,
property: Identifier,
object: Identifier,
-|};
+ parent: Node,
+};
-export type Literal = {|
+export type Literal = {
type: 'Literal',
value?: string,
rawValue?: string,
-|};
+ parent: Node,
+};
-export type CallExpression = {|
+export type CallExpression = {
type: 'CallExpression',
arguments: [Literal],
callee: Identifier | MemberExpression,
-|};
+ parent: Node,
+};
export type EslintContext = {|
report: ({message: string, node: any}) => void
diff --git a/packages/eslint-plugin-jest/src/rules/valid-expect.js b/packages/eslint-plugin-jest/src/rules/valid-expect.js
new file mode 100644
index 000000000000..b325bd9282a6
--- /dev/null
+++ b/packages/eslint-plugin-jest/src/rules/valid-expect.js
@@ -0,0 +1,61 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ */
+'use strict';
+
+/*
+ * This implementation is ported from from eslint-plugin-jasmine.
+ * MIT license, Tom Vincent.
+ */
+
+import type {EslintContext, CallExpression} from './types';
+
+module.exports = (context: EslintContext) => {
+ return {
+ CallExpression(node: CallExpression) {
+ if (node.callee.name === 'expect') {
+ // checking "expect()" arguments
+ if (node.arguments.length > 1) {
+ context.report({
+ message: 'More than one argument was passed to expect().',
+ node,
+ });
+ } else if (node.arguments.length === 0) {
+ context.report({
+ message: 'No arguments were passed to expect().',
+ node,
+ });
+ }
+
+ // matcher was not called
+ if (
+ node.parent &&
+ node.parent.type === 'MemberExpression' &&
+ node.parent.parent &&
+ node.parent.parent.type === 'ExpressionStatement'
+ ) {
+ context.report({
+ message: `"${node.parent.property.name}" was not called.`,
+ node,
+ });
+ }
+ }
+ },
+
+ // nothing called on "expect()"
+ 'CallExpression:exit'(node: CallExpression) {
+ if (
+ node.callee.name === 'expect' &&
+ node.parent.type === 'ExpressionStatement'
+ ) {
+ context.report({message: 'No assertion was called on expect().', node});
+ }
+ },
+ };
+};
diff --git a/packages/pretty-format/src/__tests__/pretty-format-test.js b/packages/pretty-format/src/__tests__/pretty-format-test.js
index 9874df348955..4517369b51ad 100644
--- a/packages/pretty-format/src/__tests__/pretty-format-test.js
+++ b/packages/pretty-format/src/__tests__/pretty-format-test.js
@@ -234,8 +234,8 @@ describe('prettyFormat()', () => {
});
it('prints a string with escapes', () => {
- expect(prettyFormat('\"-\"'), '"\\"-\\""');
- expect(prettyFormat('\\ \\\\'), '"\\\\ \\\\\\\\"');
+ expect(prettyFormat('\"-\"')).toEqual('"\\"-\\""');
+ expect(prettyFormat('\\ \\\\')).toEqual('"\\\\ \\\\\\\\"');
});
it('prints a symbol', () => {