Address code review comments

lib/CachedSource.js

@@ -8,6 +8,9 @@ const Source = require("./Source");
 const streamChunksOfSourceMap = require("./helpers/streamChunksOfSourceMap");
 const streamChunksOfRawSource = require("./helpers/streamChunksOfRawSource");
 const streamAndGetSourceAndMap = require("./helpers/streamAndGetSourceAndMap");
+const {
+	isDualStringBufferCachingEnabled
+} = require("./helpers/stringBufferUtils");
 
 const mapToBufferedMap = map => {
 	if (typeof map !== "object" || !map) return map;
@@ -63,15 +66,12 @@ class CachedSource extends Source {
 				bufferedMap: cacheEntry.bufferedMap
 			});
 		}
-		// We don't want to cache strings
-		// So if we have a caches sources
-		// create a buffer from it and only store
-		// if it was a Buffer or string
-		if (this._cachedSource) {
-			this.buffer();
-		}
 		return {
-			buffer: this._cachedBuffer,
+			// We don't want to cache strings
+			// So if we have a caches sources
+			// create a buffer from it and only store
+			// if it was a Buffer or string
+			buffer: this._cachedSource ? this.buffer() : this._cachedBuffer,
 			source:
 				this._cachedSourceType !== undefined
 					? this._cachedSourceType
@@ -112,19 +112,26 @@ class CachedSource extends Source {
 	_getCachedSource() {
 		if (this._cachedSource !== undefined) return this._cachedSource;
 		if (this._cachedBuffer && this._cachedSourceType !== undefined) {
-			return (this._cachedSource = this._cachedSourceType
+			const value = this._cachedSourceType
 				? this._cachedBuffer.toString("utf-8")
-				: this._cachedBuffer);
+				: this._cachedBuffer;
+			if (isDualStringBufferCachingEnabled()) {
+				this._cachedSource = value;
+			}
+			return value;
 		}
 	}
 
 	buffer() {
 		if (this._cachedBuffer !== undefined) return this._cachedBuffer;
 		if (this._cachedSource !== undefined) {
-			if (Buffer.isBuffer(this._cachedSource)) {
-				return (this._cachedBuffer = this._cachedSource);
+			const value = Buffer.isBuffer(this._cachedSource)
+				? this._cachedSource
+				: Buffer.from(this._cachedSource, "utf-8");
+			if (isDualStringBufferCachingEnabled()) {
+				this._cachedBuffer = value;
 			}
-			return (this._cachedBuffer = Buffer.from(this._cachedSource, "utf-8"));
+			return value;
 		}
 		if (typeof this.original().buffer === "function") {
 			return (this._cachedBuffer = this.original().buffer());
@@ -133,7 +140,11 @@ class CachedSource extends Source {
 		if (Buffer.isBuffer(bufferOrString)) {
 			return (this._cachedBuffer = bufferOrString);
 		}
-		return (this._cachedBuffer = Buffer.from(bufferOrString, "utf-8"));
+		const value = Buffer.from(bufferOrString, "utf-8");
+		if (isDualStringBufferCachingEnabled()) {
+			this._cachedBuffer = value;
+		}
+		return value;
 	}
 
 	size() {

lib/OriginalSource.js

@@ -9,6 +9,9 @@ const splitIntoLines = require("./helpers/splitIntoLines");
 const getGeneratedSourceInfo = require("./helpers/getGeneratedSourceInfo");
 const Source = require("./Source");
 const splitIntoPotentialTokens = require("./helpers/splitIntoPotentialTokens");
+const {
+	isDualStringBufferCachingEnabled
+} = require("./helpers/stringBufferUtils");
 
 class OriginalSource extends Source {
 	constructor(value, name) {
@@ -25,14 +28,22 @@ class OriginalSource extends Source {
 
 	source() {
 		if (this._value === undefined) {
-			this._value = this._valueAsBuffer.toString("utf-8");
+			const value = this._valueAsBuffer.toString("utf-8");
+			if (isDualStringBufferCachingEnabled()) {
+				this._value = value;
+			}
+			return value;
 		}
 		return this._value;
 	}
 
 	buffer() {
 		if (this._valueAsBuffer === undefined) {
-			this._valueAsBuffer = Buffer.from(this._value, "utf-8");
+			const value = Buffer.from(this._value, "utf-8");
+			if (isDualStringBufferCachingEnabled()) {
+				this._valueAsBuffer = value;
+			}
+			return value;
 		}
 		return this._valueAsBuffer;
 	}
@@ -123,11 +134,8 @@ class OriginalSource extends Source {
 	}
 
 	updateHash(hash) {
-		if (this._valueAsBuffer === undefined) {
-			this._valueAsBuffer = Buffer.from(this._value, "utf-8");
-		}
 		hash.update("OriginalSource");
-		hash.update(this._valueAsBuffer);
+		hash.update(this.buffer());
 		hash.update(this._name || "");
 	}
 }