diff --git a/__tests__/babel-plugin/__fixtures__/addVersion/code.js b/__tests__/babel-plugin/__fixtures__/addVersion/code.js
new file mode 100644
index 0000000000..9c67ab7cea
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/addVersion/code.js
@@ -0,0 +1 @@
+import module from 'example-dep';
diff --git a/__tests__/babel-plugin/__fixtures__/addVersion/options.json b/__tests__/babel-plugin/__fixtures__/addVersion/options.json
new file mode 100644
index 0000000000..5815eaa593
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/addVersion/options.json
@@ -0,0 +1,3 @@
+{
+    "addVersion": true
+}
\ No newline at end of file
diff --git a/__tests__/babel-plugin/__fixtures__/addVersion/output.js b/__tests__/babel-plugin/__fixtures__/addVersion/output.js
new file mode 100644
index 0000000000..aa4974813d
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/addVersion/output.js
@@ -0,0 +1 @@
+import module from '/web_modules/example-dep.js?v=1.2.3';
diff --git a/__tests__/babel-plugin/__fixtures__/dir/code.js b/__tests__/babel-plugin/__fixtures__/dir/code.js
new file mode 100644
index 0000000000..9c67ab7cea
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/dir/code.js
@@ -0,0 +1 @@
+import module from 'example-dep';
diff --git a/__tests__/babel-plugin/__fixtures__/dir/options.json b/__tests__/babel-plugin/__fixtures__/dir/options.json
new file mode 100644
index 0000000000..de40b2ed42
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/dir/options.json
@@ -0,0 +1,3 @@
+{
+    "dir": "test_modules"
+}
\ No newline at end of file
diff --git a/__tests__/babel-plugin/__fixtures__/dir/output.js b/__tests__/babel-plugin/__fixtures__/dir/output.js
new file mode 100644
index 0000000000..650efc46a8
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/dir/output.js
@@ -0,0 +1 @@
+import module from '/test_modules/example-dep.js';
diff --git a/__tests__/babel-plugin/__fixtures__/noOption/code.js b/__tests__/babel-plugin/__fixtures__/noOption/code.js
new file mode 100644
index 0000000000..9c67ab7cea
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/noOption/code.js
@@ -0,0 +1 @@
+import module from 'example-dep';
diff --git a/__tests__/babel-plugin/__fixtures__/noOption/options.json b/__tests__/babel-plugin/__fixtures__/noOption/options.json
new file mode 100644
index 0000000000..2c63c08510
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/noOption/options.json
@@ -0,0 +1,2 @@
+{
+}
diff --git a/__tests__/babel-plugin/__fixtures__/noOption/output.js b/__tests__/babel-plugin/__fixtures__/noOption/output.js
new file mode 100644
index 0000000000..659499992c
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/noOption/output.js
@@ -0,0 +1 @@
+import module from '/web_modules/example-dep.js';
diff --git a/__tests__/babel-plugin/__fixtures__/optionalExtensions/code.js b/__tests__/babel-plugin/__fixtures__/optionalExtensions/code.js
new file mode 100644
index 0000000000..082011b980
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/optionalExtensions/code.js
@@ -0,0 +1 @@
+import module from 'any/local/file';
diff --git a/__tests__/babel-plugin/__fixtures__/optionalExtensions/options.json b/__tests__/babel-plugin/__fixtures__/optionalExtensions/options.json
new file mode 100644
index 0000000000..e73055ac82
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/optionalExtensions/options.json
@@ -0,0 +1,3 @@
+{
+    "optionalExtensions": true
+}
\ No newline at end of file
diff --git a/__tests__/babel-plugin/__fixtures__/optionalExtensions/output.js b/__tests__/babel-plugin/__fixtures__/optionalExtensions/output.js
new file mode 100644
index 0000000000..9f5b27048b
--- /dev/null
+++ b/__tests__/babel-plugin/__fixtures__/optionalExtensions/output.js
@@ -0,0 +1 @@
+import module from '/web_modules/any/local/file.js';
diff --git a/__tests__/babel-plugin/node_modules/example-dep/package.json b/__tests__/babel-plugin/node_modules/example-dep/package.json
new file mode 100644
index 0000000000..17926cdcb9
--- /dev/null
+++ b/__tests__/babel-plugin/node_modules/example-dep/package.json
@@ -0,0 +1,6 @@
+{
+    "name": "example-dep",
+    "version": "1.2.3",
+    "main": "test.cjs",
+    "module": "test.mjs"
+  }
\ No newline at end of file
diff --git a/__tests__/babel-plugin/node_modules/example-dep/test.cjs b/__tests__/babel-plugin/node_modules/example-dep/test.cjs
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/__tests__/babel-plugin/node_modules/example-dep/test.mjs b/__tests__/babel-plugin/node_modules/example-dep/test.mjs
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/__tests__/babel-plugin/runner.js b/__tests__/babel-plugin/runner.js
new file mode 100644
index 0000000000..e74df2340f
--- /dev/null
+++ b/__tests__/babel-plugin/runner.js
@@ -0,0 +1,11 @@
+const path = require('path');
+const pluginTester = require('babel-plugin-tester').default;
+const babelPlugin = require('../../assets/babel-plugin.js');
+
+process.chdir(__dirname);
+
+pluginTester({
+  plugin: babelPlugin,
+  pluginName: 'snowpack/assets/babel-plugin.js',
+  fixtures: path.join(__dirname, '__fixtures__'),
+});
diff --git a/assets/babel-plugin.js b/assets/babel-plugin.js
index 06e21d6d7b..233679062b 100644
--- a/assets/babel-plugin.js
+++ b/assets/babel-plugin.js
@@ -8,10 +8,10 @@ function getWebDependencyName(dep) {
   return dep.replace(/\.js$/, '');
 }
 
-function getPackageVersion(package) {
+function getPackageVersion(packageName) {
   // The root module for require.resolve is @babel/cli in default, so configure here.
   const modulesPath = process.cwd() + '/node_modules';
-  const entryPointPath = require.resolve(package, {paths: [modulesPath]});
+  const entryPointPath = require.resolve(packageName, {paths: [modulesPath]});
   const json = finder(entryPointPath).next().value;
   return json.version;
 }
diff --git a/package-lock.json b/package-lock.json
index af4284f257..f993b64e4c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2189,6 +2189,28 @@
         "@types/babel__traverse": "^7.0.6"
       }
     },
+    "babel-plugin-tester": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/babel-plugin-tester/-/babel-plugin-tester-8.0.1.tgz",
+      "integrity": "sha512-5PN7FR1oxbTiA7JUdInT+vFkgu6ckYL5moRzWf5T7hAq+QX5cbcHpoXNHu1x7SQHCEZwYMhN1HzZoqeolNaO2g==",
+      "dev": true,
+      "requires": {
+        "lodash.mergewith": "^4.6.2",
+        "prettier": "^1.19.1",
+        "strip-indent": "^3.0.0"
+      },
+      "dependencies": {
+        "strip-indent": {
+          "version": "3.0.0",
+          "resolved": "https://registry.npmjs.org/strip-indent/-/strip-indent-3.0.0.tgz",
+          "integrity": "sha512-laJTa3Jb+VQpaC6DseHhF7dXVqHTfJPCRDaEbid/drOhgitgYku/letMUqOXFoWV0zIIUbjpdH2t+tYj4bQMRQ==",
+          "dev": true,
+          "requires": {
+            "min-indent": "^1.0.0"
+          }
+        }
+      }
+    },
     "babel-preset-jest": {
       "version": "24.9.0",
       "resolved": "https://registry.npmjs.org/babel-preset-jest/-/babel-preset-jest-24.9.0.tgz",
@@ -8129,6 +8151,12 @@
       "integrity": "sha1-+4m2WpqAKBgz8LdHizpRBPiY67M=",
       "dev": true
     },
+    "lodash.mergewith": {
+      "version": "4.6.2",
+      "resolved": "https://registry.npmjs.org/lodash.mergewith/-/lodash.mergewith-4.6.2.tgz",
+      "integrity": "sha512-GK3g5RPZWTRSeLSpgP8Xhra+pnjBC56q9FZYe1d5RN3TJ35dbkGy3YqBSMbyCrlbi+CM9Z3Jk5yTL7RCsqboyQ==",
+      "dev": true
+    },
     "lodash.sortby": {
       "version": "4.7.0",
       "resolved": "https://registry.npmjs.org/lodash.sortby/-/lodash.sortby-4.7.0.tgz",
@@ -8599,6 +8627,12 @@
       "integrity": "sha512-j5EctnkH7amfV/q5Hgmoal1g2QHFJRraOtmx0JpIqkxhBhI/lJSl1nMpQ45hVarwNETOoWEimndZ4QK0RHxuxQ==",
       "dev": true
     },
+    "min-indent": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/min-indent/-/min-indent-1.0.0.tgz",
+      "integrity": "sha1-z8RcN+nsDY8KDsPdTvf3w6vjklY=",
+      "dev": true
+    },
     "minimatch": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.2.tgz",
diff --git a/package.json b/package.json
index 7ce9abb0b8..03fc93159a 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,9 @@
     "lint": "prettier --check 'src/**/*.ts'",
     "publish": "pika publish",
     "version": "npm run build",
-    "test": "jest __tests__/integration/runner.js --test-timeout=15000",
+    "test": "npm run test:integration && npm run test:babel-plugin",
+    "test:integration": "jest __tests__/integration/runner.js  --test-timeout=15000",
+    "test:babel-plugin": "jest __tests__/babel-plugin/runner.js",
     "docs:build": "cat docs/* > www/index.md && npx @11ty/eleventy --config www/.eleventy.js",
     "docs:watch": "cat docs/* > www/index.md && npx @11ty/eleventy --config www/.eleventy.js --serve",
     "docs:deploy": "npm run docs:build && cd www/dist && now --prod"
@@ -66,11 +68,8 @@
     "yargs-parser": "^16.1.0"
   },
   "devDependencies": {
-    "@11ty/eleventy-plugin-syntaxhighlight": "^3.0.1",
     "@11ty/eleventy": "^0.10.0",
-    "eleventy-plugin-nesting-toc": "^1.1.0",
-    "markdown-it": "^10.0.0",
-    "markdown-it-anchor": "^5.2.5",
+    "@11ty/eleventy-plugin-syntaxhighlight": "^3.0.1",
     "@pika/pack": "^0.5.0",
     "@pika/plugin-build-node": "^0.8.1",
     "@pika/plugin-copy-assets": "^0.8.1",
@@ -78,7 +77,11 @@
     "@pika/plugin-ts-standard-pkg": "^0.8.1",
     "@types/babel__traverse": "^7.0.7",
     "@types/mkdirp": "^0.5.2",
+    "babel-plugin-tester": "^8.0.1",
+    "eleventy-plugin-nesting-toc": "^1.1.0",
     "jest": "^24.9.0",
+    "markdown-it": "^10.0.0",
+    "markdown-it-anchor": "^5.2.5",
     "prettier": "^1.18.2",
     "typescript": "^3.6.4"
   }