New: disallow identical tests

lib/rules/no-identical-tests.js

@@ -0,0 +1,53 @@
+/**
+ * @fileoverview disallow identical tests
+ * @author 薛定谔的猫<[email protected]>
+ */
+
+'use strict';
+
+const utils = require('../utils');
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'disallow identical tests',
+      category: 'Tests',
+      recommended: true,
+    },
+    fixable: null,  // or "code" or "whitespace"
+    schema: [],
+  },
+
+  create (context) {
+    // ----------------------------------------------------------------------
+    // Public
+    // ----------------------------------------------------------------------
+    const message = 'This test case should not be identical to someone else.';
+    const sourceCode = context.getSourceCode();
+
+    return {
+      Program (ast) {
+        utils.getTestInfo(context, ast).forEach(testRun => {
+          [testRun.valid, testRun.invalid].forEach(tests => {
+            const cache = Object.create(null);
+            tests.forEach(test => {
+              const testCode = sourceCode.getText(test);
+              if (cache[testCode]) {
+                context.report({
+                  node: test,
+                  message,
+                });
+              } else {
+                cache[testCode] = true;
+              }
+            });
+          });
+        });
+      },
+    };
+  },
+};

tests/lib/rules/no-identical-tests.js

@@ -0,0 +1,64 @@
+/**
+ * @fileoverview disallow identical tests
+ * @author 薛定谔的猫<[email protected]>
+ */
+
+'use strict';
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const rule = require('../../../lib/rules/no-identical-tests');
+const RuleTester = require('eslint').RuleTester;
+
+const ERROR = { message: 'This test case should not be identical to someone else.' };
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester();
+ruleTester.run('no-identical-tests', rule, {
+  valid: [
+    `
+      new RuleTester().run('foo', bar, {
+        valid: [
+          { code: 'foo' },
+          { code: 'bar' }
+        ],
+        invalid: []
+      });
+    `,
+  ],
+
+  invalid: [
+    {
+      code: `
+        new RuleTester().run('foo', bar, {
+          valid: [
+            { code: 'foo' },
+            { code: 'foo' }
+          ],
+          invalid: []
+        });
+      `,
+      errors: [ERROR],
+    },
+    {
+      code: `
+        new RuleTester().run('foo', bar, {
+          valid: [
+            { code: 'foo' },
+            { code: 'foo' },
+          ],
+          invalid: [
+            { code: 'foo', errors: ['bar'] },
+            { code: 'foo', errors: ['bar'] },
+          ]
+        });
+      `,
+      errors: [ERROR, ERROR],
+    },
+  ],
+});