Allow importing AVA as anyTest in TypeScript files

Author: pvdlg

docs/rules/use-test.md

@@ -3,6 +3,7 @@
 Translations: [Français](https://github.com/avajs/ava-docs/blob/master/fr_FR/related/eslint-plugin-ava/docs/rules/use-test.md)
 
 The convention is to import AVA and assign it to a variable named `test`. Most rules in `eslint-plugin-ava` are based on that assumption.
+In a TypeScript file (`.ts` or `.tsx`) AVA can be assigned to a variable named `anyTest` in order to define the types of `t.context` (see [Typing t.context](https://github.com/avajs/ava/blob/master/docs/recipes/typescript.md#typing-tcontext)).
 
 ### Fail
 
@@ -24,3 +25,9 @@ import test from 'ava';
 var test = require('foo');
 const test = require('foo');
 ```
+
+```ts
+import anyTest from 'ava';
+
+const test = anyTest as TestInterface<{foo: string}>;
+```

rules/use-test.js

@@ -1,4 +1,5 @@
 'use strict';
+const path = require('path');
 const espurify = require('espurify');
 const deepStrictEqual = require('deep-strict-equal');
 const util = require('../util');
@@ -24,18 +25,29 @@ function report(context, node) {
 	});
 }
 
-const create = context => ({
-	ImportDeclaration: node => {
-		if (node.source.value === 'ava' && node.specifiers[0].local.name !== 'test') {
-			report(context, node);
-		}
-	},
-	VariableDeclarator: node => {
-		if (node.id.name !== 'test' && node.init && deepStrictEqual(espurify(node.init), avaVariableDeclaratorInitAst)) {
-			report(context, node);
+const create = context => {
+	const ext = path.extname(context.getFilename());
+	const isTypeScript = ext === '.ts' || ext === '.tsx';
+
+	return {
+		ImportDeclaration: node => {
+			if (node.source.value === 'ava') {
+				const {name} = node.specifiers[0].local;
+				if (name !== 'test' && (!isTypeScript || name !== 'anyTest')) {
+					report(context, node);
+				}
+			}
+		},
+		VariableDeclarator: node => {
+			if (node.init && deepStrictEqual(espurify(node.init), avaVariableDeclaratorInitAst)) {
+				const {name} = node.id;
+				if (name !== 'test' && (!isTypeScript || name !== 'anyTest')) {
+					report(context, node);
+				}
+			}
 		}
-	}
-});
+	};
+};
 
 module.exports = {
 	create,

test/use-test.js

@@ -15,35 +15,111 @@ const errors = [{ruleId: 'use-test'}];
 
 ruleTester.run('use-test', rule, {
 	valid: [
-		'var test = require(\'ava\');',
-		'let test = require(\'ava\');',
-		'const test = require(\'ava\');',
-		'const a = 1, test = require(\'ava\'), b = 2;',
-		'const test = require(\'foo\');',
-		'import test from \'ava\';',
-		'import test, {} from \'ava\';',
-		'import test from \'foo\';'
+		{code: 'var test = require(\'ava\');', filename: 'file.js'},
+		{code: 'let test = require(\'ava\');', filename: 'file.js'},
+		{code: 'const test = require(\'ava\');', filename: 'file.js'},
+		{code: 'const a = 1, test = require(\'ava\'), b = 2;', filename: 'file.js'},
+		{code: 'const test = require(\'foo\');', filename: 'file.js'},
+		{code: 'import test from \'ava\';', filename: 'file.js'},
+		{code: 'import test, {} from \'ava\';', filename: 'file.js'},
+		{code: 'import test from \'foo\';', filename: 'file.js'},
+		{code: 'var anyTest = require(\'ava\');', filename: 'file.ts'},
+		{code: 'let anyTest = require(\'ava\');', filename: 'file.ts'},
+		{code: 'const anyTest = require(\'ava\');', filename: 'file.ts'},
+		{code: 'const a = 1, anyTest = require(\'ava\'), b = 2;', filename: 'file.ts'},
+		{code: 'const anyTest = require(\'foo\');', filename: 'file.ts'},
+		{code: 'import anyTest from \'ava\';', filename: 'file.ts'},
+		{code: 'import anyTest, {} from \'ava\';', filename: 'file.ts'},
+		{code: 'import anyTest from \'foo\';', filename: 'file.ts'},
+		{code: 'var anyTest = require(\'ava\');', filename: 'file.tsx'},
+		{code: 'let anyTest = require(\'ava\');', filename: 'file.tsx'},
+		{code: 'const anyTest = require(\'ava\');', filename: 'file.tsx'},
+		{code: 'const a = 1, anyTest = require(\'ava\'), b = 2;', filename: 'file.tsx'},
+		{code: 'const anyTest = require(\'foo\');', filename: 'file.tsx'},
+		{code: 'import anyTest from \'ava\';', filename: 'file.tsx'},
+		{code: 'import anyTest, {} from \'ava\';', filename: 'file.tsx'},
+		{code: 'import anyTest from \'foo\';', filename: 'file.tsx'}
 	],
 	invalid: [
 		{
 			code: 'var ava = require(\'ava\');',
-			errors
+			errors,
+			filename: 'file.ts'
 		},
 		{
 			code: 'let ava = require(\'ava\');',
-			errors
+			errors,
+			filename: 'file.ts'
 		},
 		{
 			code: 'const ava = require(\'ava\');',
-			errors
+			errors,
+			filename: 'file.ts'
 		},
 		{
 			code: 'const a = 1, ava = require(\'ava\'), b = 2;',
-			errors
+			errors,
+			filename: 'file.ts'
 		},
 		{
 			code: 'import ava from \'ava\';',
-			errors
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'var anyTest = require(\'ava\');',
+			errors,
+			filename: 'file.js'
+		},
+		{
+			code: 'var ava = require(\'ava\');',
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'let ava = require(\'ava\');',
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'const ava = require(\'ava\');',
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'const a = 1, ava = require(\'ava\'), b = 2;',
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'import ava from \'ava\';',
+			errors,
+			filename: 'file.ts'
+		},
+		{
+			code: 'var ava = require(\'ava\');',
+			errors,
+			filename: 'file.tsx'
+		},
+		{
+			code: 'let ava = require(\'ava\');',
+			errors,
+			filename: 'file.tsx'
+		},
+		{
+			code: 'const ava = require(\'ava\');',
+			errors,
+			filename: 'file.tsx'
+		},
+		{
+			code: 'const a = 1, ava = require(\'ava\'), b = 2;',
+			errors,
+			filename: 'file.tsx'
+		},
+		{
+			code: 'import ava from \'ava\';',
+			errors,
+			filename: 'file.tsx'
 		}
 	]
 });