stream: migrate _stream_readable use error codes

PR-URL: nodejs/node#15042
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

doc/api/errors.md

@@ -1317,6 +1317,24 @@ Node.js does not allow `stdout` or `stderr` Streams to be closed by user code.
 Used when an attempt is made to close the `process.stdout` stream. By design,
 Node.js does not allow `stdout` or `stderr` Streams to be closed by user code.
 
+<a id="ERR_STREAM_PUSH_AFTER_EOF"></a>
+### ERR_STREAM_PUSH_AFTER_EOF
+
+Used when an attempt is made to call [`stream.push()`][] after a `null`(EOF)
+has been pushed to the stream.
+
+<a id="ERR_STREAM_READ_NOT_IMPLEMENTED"></a>
+### ERR_STREAM_READ_NOT_IMPLEMENTED
+
+Used when an attempt is made to use a readable stream that has not implemented
+[`readable._read()`][].
+
+<a id="ERR_STREAM_UNSHIFT_AFTER_END_EVENT"></a>
+### ERR_STREAM_UNSHIFT_AFTER_END_EVENT
+
+Used when an attempt is made to call [`stream.unshift()`][] after the
+`end` event has been emitted.
+
 <a id="ERR_STREAM_WRAP"></a>
 ### ERR_STREAM_WRAP
 
@@ -1462,7 +1480,10 @@ closed.
 [`ERR_INVALID_ARG_TYPE`]: #ERR_INVALID_ARG_TYPE
 [`hash.digest()`]: crypto.html#crypto_hash_digest_encoding
 [`hash.update()`]: crypto.html#crypto_hash_update_data_inputencoding
+[`readable._read()`]: stream.html#stream_readable_read_size_1
 [`sign.sign()`]: crypto.html#crypto_sign_sign_privatekey_outputformat
+[`stream.push()`]: stream.html#stream_readable_push_chunk_encoding
+[`stream.unshift()`]: stream.html#stream_readable_unshift_chunk
 [`subprocess.kill()`]: child_process.html#child_process_subprocess_kill_signal
 [`subprocess.send()`]: child_process.html#child_process_subprocess_send_message_sendhandle_options_callback
 [`fs.readFileSync`]: fs.html#fs_fs_readfilesync_path_options

lib/_stream_readable.js

@@ -31,6 +31,7 @@ const util = require('util');
 const debug = util.debuglog('stream');
 const BufferList = require('internal/streams/BufferList');
 const destroyImpl = require('internal/streams/destroy');
+const errors = require('internal/errors');
 var StringDecoder;
 
 util.inherits(Readable, Stream);
@@ -233,11 +234,12 @@ function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
 
       if (addToFront) {
         if (state.endEmitted)
-          stream.emit('error', new Error('stream.unshift() after end event'));
+          stream.emit('error',
+                      new errors.Error('ERR_STREAM_UNSHIFT_AFTER_END_EVENT'));
         else
           addChunk(stream, state, chunk, true);
       } else if (state.ended) {
-        stream.emit('error', new Error('stream.push() after EOF'));
+        stream.emit('error', new errors.Error('ERR_STREAM_PUSH_AFTER_EOF'));
       } else {
         state.reading = false;
         if (state.decoder && !encoding) {
@@ -548,7 +550,7 @@ function maybeReadMore_(stream, state) {
 // for virtual (non-string, non-buffer) streams, "length" is somewhat
 // arbitrary, and perhaps not very meaningful.
 Readable.prototype._read = function(n) {
-  this.emit('error', new Error('_read() is not implemented'));
+  this.emit('error', new errors.Error('ERR_STREAM_READ_NOT_IMPLEMENTED'));
 };
 
 Readable.prototype.pipe = function(dest, pipeOpts) {

lib/internal/errors.js

@@ -325,6 +325,9 @@ E('ERR_SOCKET_CLOSED', 'Socket is closed');
 E('ERR_SOCKET_DGRAM_NOT_RUNNING', 'Not running');
 E('ERR_STDERR_CLOSE', 'process.stderr cannot be closed');
 E('ERR_STDOUT_CLOSE', 'process.stdout cannot be closed');
+E('ERR_STREAM_PUSH_AFTER_EOF', 'stream.push() after EOF');
+E('ERR_STREAM_READ_NOT_IMPLEMENTED', '_read() is not implemented');
+E('ERR_STREAM_UNSHIFT_AFTER_END_EVENT', 'stream.unshift() after end event');
 E('ERR_STREAM_WRAP', 'Stream has StringDecoder set or is in objectMode');
 E('ERR_TLS_CERT_ALTNAME_INVALID',
   'Hostname/IP does not match certificate\'s altnames: %s');

test/parallel/test-stream-readable-with-unimplemented-_read.js

@@ -1,8 +1,12 @@
 'use strict';
-require('../common');
+const common = require('../common');
 const stream = require('stream');
 const assert = require('assert');
 
 const readable = new stream.Readable();
 
-assert.throws(() => readable.read(), /not implemented/);
+assert.throws(() => readable.read(), common.expectsError({
+  code: 'ERR_STREAM_READ_NOT_IMPLEMENTED',
+  type: Error,
+  message: '_read() is not implemented'
+}));

test/parallel/test-stream-unshift-read-race.js

@@ -70,7 +70,11 @@ r._read = function(n) {
 function pushError() {
   assert.throws(function() {
     r.push(Buffer.allocUnsafe(1));
-  }, /^Error: stream\.push\(\) after EOF$/);
+  }, common.expectsError({
+    code: 'ERR_STREAM_PUSH_AFTER_EOF',
+    type: Error,
+    message: 'stream.push() after EOF'
+  }));
 }
 
 
@@ -84,7 +88,11 @@ w._write = function(chunk, encoding, cb) {
 r.on('end', common.mustCall(function() {
   assert.throws(function() {
     r.unshift(Buffer.allocUnsafe(1));
-  }, /^Error: stream\.unshift\(\) after end event$/);
+  }, common.expectsError({
+    code: 'ERR_STREAM_UNSHIFT_AFTER_END_EVENT',
+    type: Error,
+    message: 'stream.unshift() after end event'
+  }));
   w.end();
 }));