fix: cache for extracted comments (#314)

Author: evilebottnawi

src/Webpack4Cache.js

@@ -55,6 +55,8 @@ export default class Webpack4Cache {
       input,
       inputSourceMap,
       extractedComments,
+      banner,
+      shebang,
     } = cachedResult;
 
     if (map) {
@@ -70,6 +72,14 @@ export default class Webpack4Cache {
       cachedResult.source = new RawSource(code);
     }
 
+    if (banner) {
+      cachedResult.source = new ConcatSource(
+        shebang ? `${shebang}\n` : '',
+        `/*! ${banner} */\n`,
+        cachedResult.source
+      );
+    }
+
     if (extractedComments) {
       cachedResult.extractedCommentsSource = new RawSource(extractedComments);
     }
@@ -105,6 +115,8 @@ export default class Webpack4Cache {
         map: cacheData.map,
         input: cacheData.input,
         inputSourceMap: cacheData.inputSourceMap,
+        banner: cacheData.banner,
+        shebang: cacheData.shebang,
       };
 
       if (cacheData.extractedCommentsSource) {

src/index.js

@@ -323,6 +323,7 @@ class TerserPlugin {
 
           let output = await cache.get(cacheData, {
             RawSource,
+            ConcatSource,
             SourceMapSource,
           });
 
@@ -433,6 +434,8 @@ class TerserPlugin {
                     `/*! ${banner} */\n`,
                     output.source
                   );
+                  output.banner = banner;
+                  output.shebang = shebang;
                 }
               }