stream: use readableEncoding public api for child_process

PR-URL: https://github.com/nodejs/node/pull/28548
Refs: https://github.com/nodejs/node/issues/445
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

2 files changed, 11 insertions, 6 deletions

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index d6db718875..76077a117a 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -1105,6 +1105,13 @@ Object.defineProperty(Readable.prototype, 'readableObjectMode', {
   }
 });
 
+Object.defineProperty(Readable.prototype, 'readableEncoding', {
+  enumerable: false,
+  get() {
+    return this._readableState ? this._readableState.encoding : null;
+  }
+});
+
 // Pluck off n bytes from an array of buffers.
 // Length is the combined lengths of all the buffers in the list.
 // This function is designed to be inlinable, so please take care when making
diff --git a/lib/child_process.js b/lib/child_process.js
index 0d3785f0d5..43257e53df 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -266,8 +266,7 @@ function execFile(file /* , args, options, callback */) {
     if (encoding ||
       (
         child.stdout &&
-        child.stdout._readableState &&
-        child.stdout._readableState.encoding
+        child.stdout.readableEncoding
       )) {
       stdout = _stdout.join('');
     } else {
@@ -276,8 +275,7 @@ function execFile(file /* , args, options, callback */) {
     if (encoding ||
       (
         child.stderr &&
-        child.stderr._readableState &&
-        child.stderr._readableState.encoding
+        child.stderr.readableEncoding
       )) {
       stderr = _stderr.join('');
     } else {
@@ -344,7 +342,7 @@ function execFile(file /* , args, options, callback */) {
       child.stdout.setEncoding(encoding);
 
     child.stdout.on('data', function onChildStdout(chunk) {
-      const encoding = child.stdout._readableState.encoding;
+      const encoding = child.stdout.readableEncoding;
       const length = encoding ?
         Buffer.byteLength(chunk, encoding) :
         chunk.length;
@@ -367,7 +365,7 @@ function execFile(file /* , args, options, callback */) {
       child.stderr.setEncoding(encoding);
 
     child.stderr.on('data', function onChildStderr(chunk) {
-      const encoding = child.stderr._readableState.encoding;
+      const encoding = child.stderr.readableEncoding;
       const length = encoding ?
         Buffer.byteLength(chunk, encoding) :
         chunk.length;