stream: consolidate TextEncoder to single instance in utils

Four separate `TextEncoder` instances were created across `from.js`,
`pull.js`, `broadcast.js`, and `utils.js`. Consolidate to the single
instance in `utils.js` by having all files use the existing
`toUint8Array()` helper for `string`-to-`Uint8Array` conversion.

Author: jasnell

lib/internal/streams/iter/broadcast.js

@@ -22,8 +22,6 @@ const {
   TypedArrayPrototypeGetByteLength,
 } = primordials;
 
-const { TextEncoder } = require('internal/encoding');
-
 const { isError, lazyDOMException } = require('internal/util');
 
 const {
@@ -49,14 +47,13 @@ const {
 
 const {
   allUint8Array,
+  toUint8Array,
 } = require('internal/streams/iter/utils');
 
 const {
   RingBuffer,
 } = require('internal/streams/iter/ringbuffer');
 
-const encoder = new TextEncoder();
-
 // Cached resolved promise to avoid allocating a new one on every sync fast-path.
 const kResolvedPromise = PromiseResolve();
 
@@ -416,7 +413,7 @@ class BroadcastWriter {
     if (!options?.signal && !this.#closed && !this.#aborted &&
         this.#broadcast[kCanWrite]()) {
       const converted =
-        typeof chunk === 'string' ? encoder.encode(chunk) : chunk;
+        toUint8Array(chunk);
       this.#broadcast[kWrite]([converted]);
       this.#totalBytes += TypedArrayPrototypeGetByteLength(converted);
       return kResolvedPromise;
@@ -431,7 +428,7 @@ class BroadcastWriter {
       const converted = allUint8Array(chunks) ?
         ArrayPrototypeSlice(chunks) :
         ArrayPrototypeMap(chunks, (c) =>
-          (typeof c === 'string' ? encoder.encode(c) : c));
+          toUint8Array(c));
       this.#broadcast[kWrite](converted);
       for (let i = 0; i < converted.length; i++) {
         this.#totalBytes += TypedArrayPrototypeGetByteLength(converted[i]);
@@ -456,7 +453,7 @@ class BroadcastWriter {
     const converted = allUint8Array(chunks) ?
       ArrayPrototypeSlice(chunks) :
       ArrayPrototypeMap(chunks, (c) =>
-        (typeof c === 'string' ? encoder.encode(c) : c));
+        toUint8Array(c));
 
     if (this.#broadcast[kWrite](converted)) {
       for (let i = 0; i < converted.length; i++) {
@@ -485,7 +482,7 @@ class BroadcastWriter {
     if (this.#closed || this.#aborted) return false;
     if (!this.#broadcast[kCanWrite]()) return false;
     const converted =
-      typeof chunk === 'string' ? encoder.encode(chunk) : chunk;
+      toUint8Array(chunk);
     if (this.#broadcast[kWrite]([converted])) {
       this.#totalBytes += TypedArrayPrototypeGetByteLength(converted);
       return true;
@@ -499,7 +496,7 @@ class BroadcastWriter {
     const converted = allUint8Array(chunks) ?
       ArrayPrototypeSlice(chunks) :
       ArrayPrototypeMap(chunks, (c) =>
-        (typeof c === 'string' ? encoder.encode(c) : c));
+        toUint8Array(c));
     if (this.#broadcast[kWrite](converted)) {
       for (let i = 0; i < converted.length; i++) {
         this.#totalBytes += TypedArrayPrototypeGetByteLength(converted[i]);

lib/internal/streams/iter/from.js

@@ -27,7 +27,7 @@ const {
     ERR_INVALID_ARG_TYPE,
   },
 } = require('internal/errors');
-const { TextEncoder } = require('internal/encoding');
+
 const {
   isArrayBuffer,
   isPromise,
@@ -39,8 +39,9 @@ const {
   toAsyncStreamable,
 } = require('internal/streams/iter/types');
 
-// Shared TextEncoder instance for string conversion.
-const encoder = new TextEncoder();
+const {
+  toUint8Array,
+} = require('internal/streams/iter/utils');
 
 // Maximum number of chunks to yield per batch from from(Uint8Array[]).
 // Bounds peak memory when arrays flow through transforms, which must
@@ -149,7 +150,7 @@ function hasToPrimitive(obj) {
  */
 function primitiveToUint8Array(chunk) {
   if (typeof chunk === 'string') {
-    return encoder.encode(chunk);
+    return toUint8Array(chunk);
   }
   if (isArrayBuffer(chunk)) {
     return new Uint8Array(chunk);
@@ -233,7 +234,7 @@ function* normalizeSyncValue(value) {
   if (typeof value === 'object' && value !== null) {
     const str = tryStringCoercion(value);
     if (str !== null) {
-      yield encoder.encode(str);
+      yield toUint8Array(str);
       return;
     }
   }
@@ -357,7 +358,7 @@ async function* normalizeAsyncValue(value) {
   if (typeof value === 'object' && value !== null) {
     const str = tryStringCoercion(value);
     if (str !== null) {
-      yield encoder.encode(str);
+      yield toUint8Array(str);
       return;
     }
   }

lib/internal/streams/iter/pull.js

@@ -22,7 +22,6 @@ const {
     ERR_OPERATION_FAILED,
   },
 } = require('internal/errors');
-const { TextEncoder } = require('internal/encoding');
 const { isError, lazyDOMException } = require('internal/util');
 const {
   isPromise,
@@ -41,11 +40,9 @@ const {
 const {
   isPullOptions,
   parsePullArgs,
+  toUint8Array,
 } = require('internal/streams/iter/utils');
 
-// Shared TextEncoder instance for string conversion.
-const encoder = new TextEncoder();
-
 // =============================================================================
 // Type Guards and Helpers
 // =============================================================================
@@ -126,7 +123,7 @@ function* flattenTransformYieldSync(value) {
     return;
   }
   if (typeof value === 'string') {
-    yield encoder.encode(value);
+    yield toUint8Array(value);
     return;
   }
   // Must be Iterable<TransformYield>
@@ -149,7 +146,7 @@ async function* flattenTransformYieldAsync(value) {
     return;
   }
   if (typeof value === 'string') {
-    yield encoder.encode(value);
+    yield toUint8Array(value);
     return;
   }
   // Check for async iterable first