Run tests using the standalone build in an empty context (#4668)

Validate that our build is stripping all the "native" dependencies (native modules and env vars).

.circleci/config.yml

@@ -80,6 +80,17 @@ jobs:
           at: ~/prettier
       - run: yarn test:dist
 
+  # Run tests using the standalone build
+  test_prod_standalone:
+    <<: *defaults
+    steps:
+      - attach_workspace:
+          at: ~/prettier
+      - run:
+          command: yarn test:dist
+          environment:
+            TEST_STANDALONE: 1
+
 workflows:
   version: 2
   prod:
@@ -94,3 +105,6 @@ workflows:
       - test_prod_node9:
           requires:
             - build_prod
+      - test_prod_standalone:
+          requires:
+            - build_prod

jest.config.js

@@ -31,7 +31,8 @@ module.exports = {
     // If this is removed, see also scripts/build/build.js.
     "graceful-fs": "<rootDir>/tests_config/fs.js",
 
-    "prettier/local": "<rootDir>/tests_config/require_prettier.js"
+    "prettier/local": "<rootDir>/tests_config/require_prettier.js",
+    "prettier/standalone": "<rootDir>/tests_config/require_standalone.js"
   },
   transform: {}
 };

scripts/build/shims/assert.js

@@ -1,4 +1,2 @@
-module.exports = {
-  ok() {},
-  strictEqual() {}
-};
+export function ok() {}
+export function strictEqual() {}

scripts/build/shims/os.js

@@ -0,0 +1 @@
+export const EOL = "\n";

scripts/test-dist.js

@@ -20,7 +20,11 @@ shell.exec("npm init -y", { cwd: tmpDir });
 shell.exec(`npm install "${tarPath}"`, { cwd: tmpDir });
 shell.config.silent = false;
 
-const code = shell.exec("yarn test --color --runInBand", {
+const cmd = `yarn test --color --runInBand ${
+  process.env.TEST_STANDALONE ? "tests/" : ""
+}`;
+
+const code = shell.exec(cmd, {
   cwd: rootDir,
   env: Object.assign({}, process.env, {
     NODE_ENV: "production",

tests_config/require_standalone.js

@@ -0,0 +1,48 @@
+"use strict";
+
+const fs = require("fs");
+const path = require("path");
+const vm = require("vm");
+
+const sources = [
+  "standalone.js",
+  "parser-babylon.js",
+  "parser-flow.js",
+  "parser-typescript.js",
+  "parser-postcss.js",
+  "parser-graphql.js",
+  "parser-markdown.js",
+  "parser-vue.js"
+].map(filename =>
+  fs.readFileSync(path.join(process.env.PRETTIER_DIR, filename), "utf-8")
+);
+
+const sandbox = vm.createContext();
+vm.runInContext(sources.join(";"), sandbox);
+
+// TODO: maybe expose (and write tests) for `format`, `utils`, and
+// `__debug` methods
+module.exports = {
+  formatWithCursor(input, options) {
+    return vm.runInNewContext(
+      `prettier.formatWithCursor(
+        $$$input,
+        Object.assign({ plugins: prettierPlugins }, $$$options)
+      );`,
+      Object.assign({ $$$input: input, $$$options: options }, sandbox)
+    );
+  },
+
+  __debug: {
+    parse(input, options, massage) {
+      return vm.runInNewContext(
+        `prettier.__debug.parse(
+          $$$input,
+          Object.assign({ plugins: prettierPlugins }, $$$options),
+          ${JSON.stringify(massage)}
+        );`,
+        Object.assign({ $$$input: input, $$$options: options }, sandbox)
+      );
+    }
+  }
+};

tests_config/run_spec.js

@@ -2,9 +2,13 @@
 
 const fs = require("fs");
 const extname = require("path").extname;
-const prettier = require("prettier/local");
 
 const AST_COMPARE = process.env["AST_COMPARE"];
+const TEST_STANDALONE = process.env["TEST_STANDALONE"];
+
+const prettier = !TEST_STANDALONE
+  ? require("prettier/local")
+  : require("prettier/standalone");
 
 function run_spec(dirname, parsers, options) {
   /* instabul ignore if */
@@ -13,6 +17,13 @@ function run_spec(dirname, parsers, options) {
   }
 
   fs.readdirSync(dirname).forEach(filename => {
+    // We need to have a skipped test with the same name of the snapshots,
+    // so Jest doesn't mark them as obsolete.
+    if (TEST_STANDALONE && parsers.some(skipStandalone)) {
+      test.skip(filename);
+      return;
+    }
+
     const path = dirname + "/" + filename;
     if (
       extname(filename) !== ".snap" &&
@@ -116,6 +127,10 @@ function read(filename) {
   return fs.readFileSync(filename, "utf8");
 }
 
+function skipStandalone(parser) {
+  return new Set(["parse5", "glimmer"]).has(parser);
+}
+
 /**
  * Wraps a string in a marker object that is used by `./raw-serializer.js` to
  * directly print that string in a snapshot without escaping all double quotes.