test: improve assert test hygiene

Do not pollute the source tree for the test. Instead of writing to the source tree, spawn a process with the temp dir as cwd and write the file there. PR-URL: #20861 Reviewed-By: Sakthipriyan Vairamani <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Trivikram Kamat <[email protected]>

Author: Trott

test/parallel/test-assert-builtins-not-read-from-filesystem.js

@@ -1,16 +1,25 @@
-// Flags: --expose-internals
-
 'use strict';
 
-require('../common');
+// Do not read filesystem when creating AssertionError messages for code in
+// builtin modules.
 
+require('../common');
 constassert=require('assert');
-constEventEmitter=require('events');
-const{ errorCache }=require('internal/assert');
-const{ writeFileSync, unlinkSync }=require('fs');
 
-// Do not read filesystem for error messages in builtin modules.
-{
+if(process.argv[2]!=='child'){
+consttmpdir=require('../common/tmpdir');
+tmpdir.refresh();
+const{ spawnSync }=require('child_process');
+const{ output, status, error }=
+spawnSync(process.execPath,
+['--expose-internals',process.argv[1],'child'],
+{cwd: tmpdir.path,env: process.env});
+assert.ifError(error);
+assert.strictEqual(status,0,`Exit code: ${status}\n${output}`);
+}else{
+constEventEmitter=require('events');
+const{ errorCache }=require('internal/assert');
+const{ writeFileSync }=require('fs');
 conste=newEventEmitter();
 
 e.on('hello',assert);
@@ -27,18 +36,16 @@ const{writeFileSync, unlinkSync } = require('fs');
 assert.strictEqual(errorCache.size,size-1);
 constdata=`${'\n'.repeat(line-1)}${' '.repeat(column-1)}`+
 'ok(failed(badly));';
-try{
-writeFileSync(filename,data);
-assert.throws(
-()=>e.emit('hello',false),
-{
-message: 'false == true'
-}
-);
-threw=true;
-}finally{
-unlinkSync(filename);
-}
+
+writeFileSync(filename,data);
+assert.throws(
+()=>e.emit('hello',false),
+{
+message: 'false == true'
+}
+);
+threw=true;
+
 }
 assert(threw);
 }