Optionally enforce uniqueness of spec and suite names

This is off by default for backwards compatibility but can be enabled
by setting the forbidDuplicateNames env config property to true.

Fixes #1633.

lib/jasmine-core/jasmine.js

@@ -1295,6 +1295,15 @@ getJasmineRequireObj().Env = function(j$) {
        * @default true
        */
       autoCleanClosures: true,
+      /**
+       * Whether to forbid duplicate spec or suite names. If set to true, using
+       * the same name multiple times in the same immediate parent suite is an
+       * error.
+       * @name Configuration#forbidDuplicateNames
+       * @type boolean
+       * @default false
+       */
+      forbidDuplicateNames: false,
       /**
        * Whether or not to issue warnings for certain deprecated functionality
        * every time it's used. If not set or set to false, deprecation warnings
@@ -1343,7 +1352,8 @@ getJasmineRequireObj().Env = function(j$) {
         'hideDisabled',
         'stopOnSpecFailure',
         'stopSpecOnExpectationFailure',
-        'autoCleanClosures'
+        'autoCleanClosures',
+        'forbidDuplicateNames',
       ];
 
       booleanProps.forEach(function(prop) {
@@ -10272,6 +10282,16 @@ getJasmineRequireObj().Suite = function(j$) {
     );
   };
 
+  Suite.prototype.hasChildWithDescription = function(description) {
+    for (const child of this.children) {
+      if (child.description === description) {
+        return true;
+      }
+    }
+
+    return false;
+  };
+
   Object.defineProperty(Suite.prototype, 'metadata', {
     get: function() {
       if (!this.metadata_) {
@@ -10509,6 +10529,8 @@ getJasmineRequireObj().SuiteBuilder = function(j$) {
         j$.util.validateTimeout(timeout);
       }
 
+      this.checkDuplicate_(description, 'spec');
+
       const spec = this.specFactory_(description, fn, timeout, filename);
       if (this.currentDeclarationSuite_.markedExcluding) {
         spec.exclude();
@@ -10518,7 +10540,27 @@ getJasmineRequireObj().SuiteBuilder = function(j$) {
       return spec;
     }
 
+    checkDuplicate_(description, type) {
+      if (!this.env_.configuration().forbidDuplicateNames) {
+        return;
+      }
+
+      if (this.currentDeclarationSuite_.hasChildWithDescription(description)) {
+        const parentDesc =
+          this.currentDeclarationSuite_ === this.topSuite
+            ? 'top suite'
+            : `"${this.currentDeclarationSuite_.getFullName()}"`;
+        throw new Error(
+          `Duplicate ${type} name "${description}" found in ${parentDesc}`
+        );
+      }
+    }
+
     suiteFactory_(description, filename) {
+      if (this.topSuite) {
+        this.checkDuplicate_(description, 'suite');
+      }
+
       const config = this.env_.configuration();
       const parentSuite = this.currentDeclarationSuite_;
       const reportedParentSuiteId =

spec/core/SuiteBuilderSpec.js

@@ -176,6 +176,117 @@ describe('SuiteBuilder', function() {
     };
   }
 
+  describe('Duplicate name handling', function() {
+    describe('When forbidDuplicateNames is true', function() {
+      let env;
+
+      beforeEach(function() {
+        env = { configuration: () => ({ forbidDuplicateNames: true }) };
+      });
+
+      it('forbids duplicate spec names', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.describe('a suite', function() {
+            suiteBuilder.describe('a nested suite', function() {
+              suiteBuilder.it('a spec');
+              suiteBuilder.it('a spec');
+            });
+          });
+        }).toThrowError(
+          'Duplicate spec name "a spec" found in "a suite a nested suite"'
+        );
+      });
+
+      it('forbids duplicate spec names in the top suite', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.it('another spec');
+          suiteBuilder.it('another spec');
+        }).toThrowError(
+          'Duplicate spec name "another spec" found in top suite'
+        );
+      });
+
+      it('forbids duplicate suite names', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.describe('a suite', function() {
+            suiteBuilder.describe('a nested suite', function() {
+              suiteBuilder.describe('another suite', function() {
+                suiteBuilder.it('a spec');
+              });
+              suiteBuilder.describe('another suite', function() {
+                suiteBuilder.it('a spec');
+              });
+            });
+          });
+        }).toThrowError(
+          'Duplicate suite name "another suite" found in "a suite a nested suite"'
+        );
+      });
+
+      it('forbids duplicate suite names in the top suite', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.describe('a suite', function() {
+            suiteBuilder.it('a spec');
+          });
+          suiteBuilder.describe('a suite', function() {
+            suiteBuilder.it('a spec');
+          });
+        }).toThrowError('Duplicate suite name "a suite" found in top suite');
+      });
+
+      it('allows spec and suite names to be duplicated in different suites', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.describe('suite a', function() {
+            suiteBuilder.describe('dupe suite', function() {
+              suiteBuilder.it('dupe spec');
+              suiteBuilder.describe('child suite', function() {
+                suiteBuilder.it('dupe spec');
+              });
+            });
+          });
+          suiteBuilder.describe('suite b', function() {
+            suiteBuilder.describe('dupe suite', function() {
+              suiteBuilder.it('dupe spec');
+            });
+          });
+        }).not.toThrow();
+      });
+    });
+
+    describe('When forbidDuplicateNames is false', function() {
+      let env;
+
+      beforeEach(function() {
+        env = { configuration: () => ({ forbidDuplicateNames: false }) };
+      });
+
+      it('allows duplicate spec and suite names', function() {
+        const suiteBuilder = new jasmineUnderTest.SuiteBuilder({ env });
+
+        expect(function() {
+          suiteBuilder.describe('dupe suite', function() {
+            suiteBuilder.it('dupe spec');
+            suiteBuilder.it('dupe spec');
+          });
+          suiteBuilder.describe('dupe suite', function() {
+            suiteBuilder.it('dupe spec');
+            suiteBuilder.it('dupe spec');
+          });
+        }).not.toThrow();
+      });
+    });
+  });
+
   describe('#parallelReset', function() {
     it('resets the top suite result', function() {
       jasmineUnderTest.Suite.prototype.handleException.and.callThrough();

spec/core/SuiteSpec.js

@@ -378,4 +378,31 @@ describe('Suite', function() {
       );
     });
   });
+
+  describe('#hasChildWithDescription', function() {
+    it('returns true if there is a child with the given description', function() {
+      const subject = new jasmineUnderTest.Suite({});
+      const description = 'a spec';
+      subject.addChild({ description });
+
+      expect(subject.hasChildWithDescription(description)).toBeTrue();
+    });
+
+    it('returns false if there is no child with the given description', function() {
+      const subject = new jasmineUnderTest.Suite({});
+      subject.addChild({ description: 'a different spec' });
+
+      expect(subject.hasChildWithDescription('a spec')).toBeFalse();
+    });
+
+    it('does not recurse into child suites', function() {
+      const subject = new jasmineUnderTest.Suite({});
+      const childSuite = new jasmineUnderTest.Suite({});
+      subject.addChild(childSuite);
+      const description = 'a spec';
+      childSuite.addChild(description);
+
+      expect(subject.hasChildWithDescription('a spec')).toBeFalse();
+    });
+  });
 });

spec/core/integration/EnvSpec.js

@@ -4444,6 +4444,15 @@ describe('Env integration', function() {
     });
   });
 
+  it('forbids duplicates when forbidDuplicateNames is true', function() {
+    env.configure({ forbidDuplicateNames: true });
+    env.it('a spec');
+
+    expect(function() {
+      env.it('a spec');
+    }).toThrowError('Duplicate spec name "a spec" found in top suite');
+  });
+
   function browserEventMethods() {
     return {
       listeners_: { error: [], unhandledrejection: [] },

src/core/Env.js

@@ -138,6 +138,15 @@ getJasmineRequireObj().Env = function(j$) {
        * @default true
        */
       autoCleanClosures: true,
+      /**
+       * Whether to forbid duplicate spec or suite names. If set to true, using
+       * the same name multiple times in the same immediate parent suite is an
+       * error.
+       * @name Configuration#forbidDuplicateNames
+       * @type boolean
+       * @default false
+       */
+      forbidDuplicateNames: false,
       /**
        * Whether or not to issue warnings for certain deprecated functionality
        * every time it's used. If not set or set to false, deprecation warnings
@@ -186,7 +195,8 @@ getJasmineRequireObj().Env = function(j$) {
         'hideDisabled',
         'stopOnSpecFailure',
         'stopSpecOnExpectationFailure',
-        'autoCleanClosures'
+        'autoCleanClosures',
+        'forbidDuplicateNames'
       ];
 
       booleanProps.forEach(function(prop) {

src/core/Suite.js

@@ -251,6 +251,16 @@ getJasmineRequireObj().Suite = function(j$) {
     );
   };
 
+  Suite.prototype.hasChildWithDescription = function(description) {
+    for (const child of this.children) {
+      if (child.description === description) {
+        return true;
+      }
+    }
+
+    return false;
+  };
+
   Object.defineProperty(Suite.prototype, 'metadata', {
     get: function() {
       if (!this.metadata_) {

src/core/SuiteBuilder.js

@@ -161,6 +161,8 @@ getJasmineRequireObj().SuiteBuilder = function(j$) {
         j$.util.validateTimeout(timeout);
       }
 
+      this.checkDuplicate_(description, 'spec');
+
       const spec = this.specFactory_(description, fn, timeout, filename);
       if (this.currentDeclarationSuite_.markedExcluding) {
         spec.exclude();
@@ -170,7 +172,27 @@ getJasmineRequireObj().SuiteBuilder = function(j$) {
       return spec;
     }
 
+    checkDuplicate_(description, type) {
+      if (!this.env_.configuration().forbidDuplicateNames) {
+        return;
+      }
+
+      if (this.currentDeclarationSuite_.hasChildWithDescription(description)) {
+        const parentDesc =
+          this.currentDeclarationSuite_ === this.topSuite
+            ? 'top suite'
+            : `"${this.currentDeclarationSuite_.getFullName()}"`;
+        throw new Error(
+          `Duplicate ${type} name "${description}" found in ${parentDesc}`
+        );
+      }
+    }
+
     suiteFactory_(description, filename) {
+      if (this.topSuite) {
+        this.checkDuplicate_(description, 'suite');
+      }
+
       const config = this.env_.configuration();
       const parentSuite = this.currentDeclarationSuite_;
       const reportedParentSuiteId =