esm: tests for correctly detecting module types of symlinks

Author: GeoffreyBooth

test/es-module/test-esm-symlink-type.js

@@ -0,0 +1,68 @@
+'use strict';
+const common = require('../common');
+const path = require('path');
+const assert = require('assert');
+const exec = require('child_process').execFile;
+
+// Check that running the symlink executes the target as the correct type
+const symlinks = [
+  {
+    source: 'extensionless-symlink-to-mjs-file',
+    prints: '.mjs file',
+    errorsWithPreserveSymlinksMain: false
+  }, {
+    source: 'extensionless-symlink-to-cjs-file',
+    prints: '.cjs file',
+    errorsWithPreserveSymlinksMain: false
+  }, {
+    source: 'extensionless-symlink-to-file-in-module-scope',
+    prints: 'package-type-module',
+    // The package scope of the symlinks' sources is commonjs, and this
+    // symlink's target is a .js file in a module scope, so when the scope
+    // is evaluated based on the source (commonjs) this esm file should error
+    errorsWithPreserveSymlinksMain: true
+  }, {
+    source: 'extensionless-symlink-to-file-in-explicit-commonjs-scope',
+    prints: 'package-type-commonjs',
+    errorsWithPreserveSymlinksMain: false
+  }, {
+    source: 'extensionless-symlink-to-file-in-implicit-commonjs-scope',
+    prints: 'package-without-type',
+    errorsWithPreserveSymlinksMain: false
+  }
+];
+
+symlinks.forEach((symlink) => {
+  const argv = [
+    path.join(__dirname, '../fixtures/es-modules/', symlink.source)
+  ];
+  // TODO: Update when --experimental-modules is unflagged
+  const flags = [
+    '--experimental-modules',
+    '--experimental-modules --preserve-symlinks-main'
+  ];
+  flags.forEach((nodeOptions) => {
+    const opts = {
+      env: Object.assign({}, process.env, { NODE_OPTIONS: nodeOptions }),
+      maxBuffer: 1e6,
+    };
+    exec(process.execPath, argv, opts, common.mustCall(
+      (err, stdout, stderr) => {
+        if (nodeOptions.includes('--preserve-symlinks-main')) {
+          if (symlink.errorsWithPreserveSymlinksMain &&
+              stderr.includes('Error')) return;
+          else if (!symlink.errorsWithPreserveSymlinksMain &&
+                    stdout.includes(symlink.prints)) return;
+          assert.fail(`For ${JSON.stringify(symlink)}, ${
+            (symlink.errorsWithPreserveSymlinksMain) ?
+              'failed to error' : 'errored unexpectedly'
+          } with --preserve-symlinks-main`);
+        } else {
+          if (stdout.includes(symlink.prints)) return;
+          assert.fail(`For ${JSON.stringify(symlink)}, failed to find ` +
+            `${symlink.prints} in: <\n${stdout}\n>`);
+        }
+      }
+    ));
+  });
+});

test/fixtures/es-modules/extensionless-symlink-to-cjs-file

@@ -0,0 +1 @@
+./cjs-file.cjs

test/fixtures/es-modules/extensionless-symlink-to-file-in-explicit-commonjs-scope

@@ -0,0 +1 @@
+./package-type-commonjs/index.js

test/fixtures/es-modules/extensionless-symlink-to-file-in-implicit-commonjs-scope

@@ -0,0 +1 @@
+./package-without-type/index.js

test/fixtures/es-modules/extensionless-symlink-to-file-in-module-scope

@@ -0,0 +1 @@
+./package-type-module/index.js

test/fixtures/es-modules/extensionless-symlink-to-mjs-file

@@ -0,0 +1 @@
+./mjs-file.mjs