fix: only hoist counter for a smaller subset of function declarations

istanbuljs-archived-repos · Jan 4, 2017 · 9f8931e · 9f8931e
1 parent 4fe4dca
commit 9f8931e
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Showing 2 changed files with 42 additions and 2 deletions.
diff --git a/src/visitor.js b/src/visitor.js
@@ -145,11 +145,15 @@ class VisitState {
         } else if (path.isStatement()) {
             path.insertBefore(T.expressionStatement(increment));
         } else if ((path.isFunctionExpression() || path.isArrowFunctionExpression()) && T.isVariableDeclarator(path.parentPath)) {
-            const parent = path.findParent((path) => path.parentPath.isProgram());
-            if (parent) {
+            // make an attempt to hoist the statement counter, so that
+            // function names are maintained.
+            const parent = path.parentPath.parentPath;
+            if (parent && (T.isProgram(parent.parentPath) || T.isBlockStatement(parent.parentPath))) {
                 parent.insertBefore(T.expressionStatement(
                     increment
                 ));
+            } else {
+                path.replaceWith(T.sequenceExpression([increment, path.node]));
             }
         } else /* istanbul ignore else: not expected */ if (path.isExpression()) {
             path.replaceWith(T.sequenceExpression([increment, path.node]));

diff --git a/test/specs/functions.yaml b/test/specs/functions.yaml
@@ -110,3 +110,39 @@ tests:
     functions: {'0': 0, '1': 0}
     statements: {'0': 1, '1': 1, '2': 1}
     guard: isInferredFunctionNameAvailable
+
+
+---
+name: function declaration assignment name (top-level)
+guard: isInferredFunctionNameAvailable
+code: |
+  const foo = function() {}
+  var bar = function() {}
+  output = foo.name + ' ' + bar.name;
+tests:
+  - name: properly sets function name
+    out: 'foo bar'
+    lines: {'1': 1, '2': 1, '3': 1}
+    functions: {'0': 0, '1': 0}
+    statements: {'0': 1, '1': 1, '2': 1}
+    guard: isInferredFunctionNameAvailable
+
+---
+name: function declaration assignment name (in function)
+guard: isInferredFunctionNameAvailable
+code: |
+  function a () {
+    const foo = function () {}
+  }
+  function b () {
+    const bar = function () {}
+    return bar.name
+  }
+  output = b()
+tests:
+  - name: properly sets function name
+    out: 'bar'
+    lines: {'2': 0, '5': 1, '6': 1, '8': 1}
+    functions: {'0': 0, '1': 0, '2': 1, '3': 0}
+    statements: {'0': 0, '1': 1, '2': 1, '3': 1}
+    guard: isInferredFunctionNameAvailable