make contract function name a true property, not a derived property

in response to sinonjs/sinon#2203
Toryt · Jun 1, 2020 · 2c63d7d · 2c63d7d
1 parent 351c5c2
commit 2c63d7d
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Showing 2 changed files with 18 additions and 7 deletions.
diff --git a/lib/IV/AbstractContract.js b/lib/IV/AbstractContract.js
@@ -275,13 +275,17 @@ AbstractContract.bless = function bless (contractFunction, contract, implFunctio
       we reach the 'syntactic position' (a.k.a, we assign the contract function to a variable or property with
       a name), it will already have the name `contractFunction` we need internally. Therefor, we will explicitly set
       the name, based on the name of implementation function.
-      The Firefox feature `displayName` will not be used.  */
+      The Firefox feature `displayName` will not be used.
+      This is a real property, and not a derived property. Earlier, it was, but this was changed in response to
+      https://github.com/sinonjs/sinon/issues/2203 */
     // IDEA we might also add a name property to a Contract, and combine it with that
-    property.frozenDerived(
-      contractFunction,
-      'name',
-      report.conciseCondition.bind(null, report.namePrefix, implFunction)
-    )
+    const implNamePropertyDescriptor = Object.getOwnPropertyDescriptor(implFunction, 'name')
+    Object.defineProperty(contractFunction, 'name', {
+      configurable: implNamePropertyDescriptor.configurable,
+      enumerable: implNamePropertyDescriptor.enumerable,
+      writable: implNamePropertyDescriptor.writable,
+      value: report.conciseCondition(report.namePrefix, implFunction)
+    })
   }
 }
 

diff --git a/test/02.IV/02.2.AbstractContractTest.js b/test/02.IV/02.2.AbstractContractTest.js
@@ -127,11 +127,18 @@ describe('IV/AbstractContract', function () {
       contractFunction.location.should.equal(location)
       testUtil.expectOwnFrozenProperty(contractFunction, 'bind')
       contractFunction.bind.should.equal(AbstractContract.bindContractFunction)
-      testUtil.expectFrozenDerivedPropertyOnAPrototype(contractFunction, 'name')
       contractFunction.should.have.ownProperty('name')
       contractFunction.name.should.equal(
         report.conciseCondition(AbstractContract.namePrefix, contractFunction.implementation)
       )
+      const implFunctionNamePropDesc = Object.getOwnPropertyDescriptor(implFunction, 'name')
+      delete implFunctionNamePropDesc.value
+      const contractFunctionNamePropDesc = Object.getOwnPropertyDescriptor(contractFunction, 'name')
+      contractFunctionNamePropDesc.value.should.equal(
+        report.conciseCondition(AbstractContract.namePrefix, contractFunction.implementation)
+      )
+      delete contractFunctionNamePropDesc.value
+      contractFunctionNamePropDesc.should.deepEqual(implFunctionNamePropDesc)
     })
   })