fixup! esm: refactor esm tests out of test/message

Author: GeoffreyBooth

test/es-module/test-esm-export-not-found.mjs

@@ -28,7 +28,7 @@ const importStatementMultiline = `import {
     stderr += data;
   });
   child.on('close', () => {
-    ok(stderr.toString().includes(
+    ok(stderr.includes(
       'SyntaxError: The requested module \'./module-named-exports.mjs\' ' +
       'does not provide an export named \'notfound\''
     ));

test/es-module/test-esm-import-json-named-export.mjs

@@ -15,7 +15,7 @@ child.stderr.on('data', (data) => {
   stderr += data;
 });
 child.on('close', () => {
-  ok(stderr.toString().includes(
+  ok(stderr.includes(
     'SyntaxError: The requested module \'../experimental.json\' ' +
     'does not provide an export named \'ofLife\''
   ));

test/es-module/test-esm-loader-not-found.mjs

@@ -16,7 +16,6 @@ child.stderr.on('data', (data) => {
   stderr += data;
 });
 child.on('close', () => {
-  stderr = stderr.toString();
   ok(stderr.includes(
     'Error [ERR_MODULE_NOT_FOUND]: Cannot find package \'i-dont-exist\' ' +
     'imported from'

test/es-module/test-esm-loader-obsolete-hooks.mjs

@@ -18,7 +18,6 @@ child.stderr.on('data', (data) => {
   stderr += data;
 });
 child.on('close', () => {
-  stderr = stderr.toString();
   ok(stderr.includes(
     'DeprecationWarning: Obsolete loader hook(s) supplied and will be ' +
     'ignored: dynamicInstantiate, getFormat, getSource, transformSource'

test/es-module/test-esm-loader-with-syntax-error.mjs

@@ -16,7 +16,6 @@ child.stderr.on('data', (data) => {
   stderr += data;
 });
 child.on('close', () => {
-  stderr = stderr.toString();
   ok(stderr.includes(
     'SyntaxError: Malformed arrow function parameter list'
   ));

test/es-module/test-esm-module-not-found-commonjs-hint.mjs

@@ -28,6 +28,6 @@ import { execPath } from 'process';
     stderr += data;
   });
   child.on('close', () => {
-    ok(stderr.toString().includes(expected));
+    ok(stderr.includes(expected));
   });
 });

test/es-module/test-esm-syntax-error.mjs

@@ -14,7 +14,7 @@ child.stderr.on('data', (data) => {
   stderr += data;
 });
 child.on('close', () => {
-  ok(stderr.toString().includes(
+  ok(stderr.includes(
     'SyntaxError: Malformed arrow function parameter list'
   ));
 });