test: remove internal errorCache property

The internal `assert` modules `errorCache` property is exposed only for
testing. The one test that used it is rewritten here to not use it.

This has the following advantages:

* The test now makes sure that there is an empty cache in a more robust
  way. Instead of relying on the internal implementation of
  `errorCache`, it simply spawns a separate process.
* One less test using the `--expose-internals` flag.

PR-URL: #23304
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

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

@@ -5,47 +5,44 @@
 
 require('../common');
 const assert = require('assert');
+const EventEmitter = require('events');
+const e = new EventEmitter();
+e.on('hello', assert);
 
 if (process.argv[2] !== 'child') {
   const tmpdir = 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 {
-  const EventEmitter = require('events');
-  const { errorCache } = require('internal/assert');
-  const { writeFileSync } = require('fs');
-  const e = new EventEmitter();
-
-  e.on('hello', assert);
 
   let threw = false;
   try {
     e.emit('hello', false);
   } catch (err) {
     const frames = err.stack.split('\n');
-    const [, filename, line, column] = frames[1].match(/\((.+):(\d+):(\d+)\)/);
-    // Reset the cache to check again
-    const size = errorCache.size;
-    errorCache.delete(`${filename}${line - 1}${column - 1}`);
-    assert.strictEqual(errorCache.size, size - 1);
-    const data = `${'\n'.repeat(line - 1)}${' '.repeat(column - 1)}` +
-                 'ok(failed(badly));';
+    const [, filename, , ] = frames[1].match(/\((.+):(\d+):(\d+)\)/);
+    // Spawn a child process to avoid the error having been cached in the assert
+    // module's `errorCache` Map.
 
-    writeFileSync(filename, data);
-    assert.throws(
-      () => e.emit('hello', false),
-      {
-        message: 'false == true'
-      }
-    );
+    const { output, status, error } =
+      spawnSync(process.execPath,
+                [process.argv[1], 'child', filename],
+                { cwd: tmpdir.path, env: process.env });
+    assert.ifError(error);
+    assert.strictEqual(status, 0, `Exit code: ${status}\n${output}`);
     threw = true;
-
   }
-  assert(threw);
+  assert.ok(threw);
+} else {
+  const { writeFileSync } = require('fs');
+  const [, , , filename, line, column] = process.argv;
+  const data = `${'\n'.repeat(line - 1)}${' '.repeat(column - 1)}` +
+               'ok(failed(badly));';
+
+  writeFileSync(filename, data);
+  assert.throws(
+    () => e.emit('hello', false),
+    {
+      message: 'false == true'
+    }
+  );
 }