Fixed reset of BABEL_ENV when options.forceEnv is used

src/index.js

@@ -46,7 +46,7 @@ const transpile = function(source, options) {
   try {
     result = babel.transform(source, options);
   } catch (error) {
-    if (forceEnv) process.env.BABEL_ENV = tmpEnv;
+    if (forceEnv) restoreBabelEnv(tmpEnv);
     if (error.message && error.codeFrame) {
       let message = error.message;
       let name;
@@ -73,7 +73,7 @@ const transpile = function(source, options) {
     map.sourcesContent = [source];
   }
 
-  if (forceEnv) process.env.BABEL_ENV = tmpEnv;
+  if (forceEnv) restoreBabelEnv(tmpEnv);
 
   return {
     code: code,
@@ -82,6 +82,14 @@ const transpile = function(source, options) {
   };
 };
 
+function restoreBabelEnv(prevValue) {
+  if (prevValue === undefined) {
+    delete process.env.BABEL_ENV;
+  } else {
+    process.env.BABEL_ENV = prevValue;
+  }
+}
+
 function passMetadata(s, context, metadata) {
   if (context[s]) {
     context[s](metadata);

test/loader.test.js

@@ -117,3 +117,121 @@ test.cb("should use correct env", (t) => {
     t.end();
   });
 });
+
+test.serial.cb("should not polute BABEL_ENV after using forceEnv", (t) => {
+  const initialBabelEnv = process.env.BABEL_ENV;
+
+  const config = {
+    entry: path.join(__dirname, "fixtures/basic.js"),
+    output: {
+      path: t.context.directory,
+    },
+    module: {
+      loaders: [
+        {
+          test: /\.jsx?/,
+          loader: babelLoader,
+          query: {
+            forceEnv: "testenv",
+            env: {
+              testenv: {
+                presets: ["es2015"],
+              },
+            }
+          },
+          exclude: /node_modules/,
+        },
+      ],
+    },
+  };
+
+  webpack(config, () => {
+    t.truthy(process.env.BABEL_ENV === initialBabelEnv);
+    t.end();
+  });
+});
+
+test.serial.cb("should not polute BABEL_ENV after using forceEnv (on exception)", (t) => {
+  const initialBabelEnv = process.env.BABEL_ENV;
+
+  const config = {
+    entry: path.join(__dirname, "fixtures/basic.js"),
+    output: {
+      path: t.context.directory,
+    },
+    module: {
+      loaders: [
+        {
+          test: /\.jsx?/,
+          loader: babelLoader,
+          query: {
+            forceEnv: "testenv",
+            env: {
+              testenv: {
+                presets: ["es2015asd"],
+              },
+            }
+          },
+          exclude: /node_modules/,
+        },
+      ],
+    },
+  };
+
+  webpack(config, () => {
+    t.truthy(process.env.BABEL_ENV === initialBabelEnv);
+    t.end();
+  });
+});
+
+test.serial.cb("should not change BABEL_ENV when using forceEnv", (t) => {
+  const initialBabelEnv = process.env.BABEL_ENV;
+
+  process.env.BABEL_ENV = "nontestenv";
+
+  const config = {
+    entry: path.join(__dirname, "fixtures/basic.js"),
+    output: {
+      path: t.context.directory,
+    },
+    module: {
+      loaders: [
+        {
+          test: /\.jsx?/,
+          loader: babelLoader,
+          query: {
+            forceEnv: "testenv",
+            env: {
+              testenv: {
+                presets: ["es2015abc"],
+              },
+              nontestenv: {
+                presets: ["es2015xzy"]
+              }
+            }
+          },
+          exclude: /node_modules/,
+        },
+      ],
+    },
+  };
+
+  webpack(config, (err, stats) => {
+    t.is(err, null);
+
+    t.true(stats.compilation.errors.length === 1);
+
+    t.truthy(stats.compilation.errors[0].message.match(/es2015abc/));
+    t.falsy(stats.compilation.errors[0].message.match(/es2015xyz/));
+
+    t.truthy("nontestenv" === process.env.BABEL_ENV);
+
+    if (initialBabelEnv !== undefined) {
+      process.env.BABEL_ENV = initialBabelEnv;
+    } else {
+      delete process.env.BABEL_ENV;
+    }
+
+    t.end();
+  });
+});