fix: container is falsy error with block scoping transform (#291)

.github/workflows/ci.yaml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [12, 14, 16]
+        node: [12, 14, 16, 18, 20, 22]
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1

fixtures/issue-289.js

@@ -0,0 +1,4 @@
+for (let f; ; ) {
+  f = "0";
+  () => (0 ? 1 : parseInt(f));
+}

package.json

@@ -16,10 +16,11 @@
     "test-exclude": "^6.0.0"
   },
   "devDependencies": {
-    "@babel/cli": "^7.7.5",
-    "@babel/core": "^7.7.5",
-    "@babel/plugin-transform-modules-commonjs": "^7.7.5",
-    "@babel/register": "^7.7.4",
+    "@babel/cli": "^7.24.1",
+    "@babel/core": "^7.24.1",
+    "@babel/plugin-transform-block-scoping": "^7.24.1",
+    "@babel/plugin-transform-modules-commonjs": "^7.24.1",
+    "@babel/register": "^7.23.7",
     "chai": "^4.2.0",
     "coveralls": "^3.0.9",
     "cross-env": "^6.0.3",

src/index.js

@@ -128,6 +128,7 @@ export default declare(api => {
             inputSourceMap
           })
           this.__dv__.enter(path)
+          path.scope.crawl()
         },
         exit (path) {
           if (!this.__dv__) {

test/babel-plugin-istanbul.js

@@ -327,5 +327,20 @@ describe('babel-plugin-istanbul', function () {
       result.code.should.match(/_path.*\.resolve\)\(_path\)/)
       result.code.should.not.match(/_path\.resolve\)\(_path\)/)
     })
+
+    // regression test for https://github.com/istanbuljs/babel-plugin-istanbul/issues/289
+    it('should instrument: for (let f; ; ) { ...', function () {
+      var result = babel.transformFileSync('./fixtures/issue-289.js', {
+        babelrc: false,
+        configFile: false,
+        plugins: [
+          '@babel/plugin-transform-block-scoping',
+          [makeVisitor, {
+            include: ['fixtures/issue-289.js']
+          }]
+        ]
+      })
+      console.log(result)
+    })
   })
 })