Chore: improve test coverage of no-identical-tests rule (#153)

Author: bmish

lib/rules/no-identical-tests.js

@@ -21,13 +21,15 @@ module.exports = {
     },
     fixable: 'code',
     schema: [],
+    messages: {
+      identical: 'This test case is identical to another case.',
+    },
   },
 
   create (context) {
     // ----------------------------------------------------------------------
     // Public
     // ----------------------------------------------------------------------
-    const message = 'This test case is identical to another case.';
     const sourceCode = context.getSourceCode();
 
     // ----------------------------------------------------------------------
@@ -46,8 +48,8 @@ module.exports = {
         return sourceCode.getText(testA) === sourceCode.getText(testB);
       }
 
-      const propertiesA = testA.properties || [];
-      const propertiesB = testB.properties || [];
+      const propertiesA = testA.properties;
+      const propertiesB = testB.properties;
 
       // if properties length not eq; return false;
       if (propertiesA.length !== propertiesB.length) {
@@ -78,7 +80,7 @@ module.exports = {
               if (cache.some(item => eq(item, test))) {
                 context.report({
                   node: test,
-                  message,
+                  messageId: 'identical',
                   fix (fixer) {
                     const start = sourceCode.getTokenBefore(test);
                     const end = sourceCode.getTokenAfter(test);

package.json

@@ -33,9 +33,9 @@
     "eslint-utils": "^2.1.0"
   },
   "nyc": {
-    "branches": 96,
+    "branches": 97,
     "functions": 98,
-    "lines": 98,
+    "lines": 99,
     "statements": 98
   },
   "devDependencies": {

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

@@ -12,7 +12,8 @@
 const rule = require('../../../lib/rules/no-identical-tests');
 const RuleTester = require('eslint').RuleTester;
 
-const ERROR = { message: 'This test case is identical to another case.' };
+const ERROR_OBJECT_TEST = { messageId: 'identical', type: 'ObjectExpression' };
+const ERROR_STRING_TEST = { messageId: 'identical', type: 'Literal' };
 
 // ------------------------------------------------------------------------------
 // Tests
@@ -46,6 +47,26 @@ ruleTester.run('no-identical-tests', rule, {
         invalid: []
       });
     `,
+    // Object and string test.
+    `
+      new RuleTester().run('foo', bar, {
+        valid: [
+          { code: 'foo' },
+          'foo',
+        ],
+        invalid: []
+      });
+    `,
+    // One test object with more properties than the other.
+    `
+      new RuleTester().run('foo', bar, {
+        valid: [
+          { code: 'foo' },
+          { code: 'foo', options: [{}] },
+        ],
+        invalid: []
+      });
+    `,
   ],
 
   invalid: [
@@ -67,7 +88,7 @@ ruleTester.run('no-identical-tests', rule, {
           invalid: []
         });
       `,
-      errors: [ERROR],
+      errors: [ERROR_OBJECT_TEST],
     },
     {
       code: `
@@ -87,7 +108,7 @@ ruleTester.run('no-identical-tests', rule, {
           invalid: []
         });
       `,
-      errors: [ERROR],
+      errors: [ERROR_OBJECT_TEST],
     },
     {
       code: `
@@ -112,7 +133,7 @@ ruleTester.run('no-identical-tests', rule, {
           ]
         });
       `,
-      errors: [ERROR, ERROR],
+      errors: [ERROR_OBJECT_TEST, ERROR_OBJECT_TEST],
     },
     {
       code: `
@@ -132,7 +153,28 @@ ruleTester.run('no-identical-tests', rule, {
           invalid: []
         });
       `,
-      errors: [ERROR],
+      errors: [ERROR_OBJECT_TEST],
+    },
+    {
+      // Empty objects.
+      code: `
+        new RuleTester().run('foo', bar, {
+          valid: [
+            {},
+            {},
+          ],
+          invalid: []
+        });
+      `,
+      output: `
+        new RuleTester().run('foo', bar, {
+          valid: [
+            {},
+          ],
+          invalid: []
+        });
+      `,
+      errors: [ERROR_OBJECT_TEST],
     },
     {
       code: `
@@ -152,7 +194,7 @@ ruleTester.run('no-identical-tests', rule, {
           invalid: []
         });
       `,
-      errors: [ERROR],
+      errors: [ERROR_STRING_TEST],
     },
   ],
 });