Do not treat inheritance constructors as branches (#594)

lib/registrar.js

@@ -129,7 +129,7 @@ class Registrar {
         }
 
         // Add modifier branch coverage
-        if (!this.enabled.modifiers) continue;
+        if (!this.enabled.modifiers || expression.isConstructor) continue;
 
         this.addNewModifierBranch(contract, modifier);
         this._createInjectionPoint(

test/sources/solidity/contracts/modifiers/constructor.sol

@@ -0,0 +1,17 @@
+pragma solidity ^0.7.0;
+
+contract Parent {
+  string public name;
+
+  constructor(string memory _name) public {
+    name = _name;
+  }
+}
+
+contract Test is Parent {
+    constructor() public Parent("Test") {}
+
+    function a() public {
+      uint x = 5;
+    }
+}

test/units/modifiers.js

@@ -160,4 +160,10 @@ describe('modifiers', () => {
       1: 1, 2: 1, 3: 1
     });
   });
+
+  it('should *not* treat constructor inheritance invocations as branches', async function() {
+    const mapping = await setupAndRun('modifiers/constructor');
+    assert.deepEqual(mapping[util.filePath].b, {});
+  });
+
 });