fix: copy static image as it is if image compression fail (#887)

* fix: fail to copy static image due to image compression on build

* add changelog

CHANGELOG.md

@@ -34,6 +34,7 @@ Thank you to the following contributors who helped with this release:
 - Docusaurus own search will now search the docs in the correct language & version [\#859](https://github.com/facebook/Docusaurus/pull/859)
 - Fix phrase emphasis not italicized [\#850](https://github.com/facebook/Docusaurus/pull/850)
 - Blogpost summary for blog feed is now properly truncated [\#880](https://github.com/facebook/Docusaurus/pull/880)
+- Fix failure to copy static image if image compression fail [\#887](https://github.com/facebook/Docusaurus/pull/887)
 
 **Chore and Maintenance**
 - Remove unused files [\#881](https://github.com/facebook/Docusaurus/pull/881)

lib/server/generate.js

@@ -247,11 +247,9 @@ async function execute() {
       !commander.skipImageCompression
     ) {
       const parts = normalizedFile.split(`${sep}static${sep}`);
-      const targetDirectory = join(
-        buildDir,
-        parts[1].substring(0, parts[1].lastIndexOf(sep))
-      );
-      mkdirp.sync(path.dirname(targetDirectory));
+      const targetFile = join(buildDir, parts[1]);
+      const targetDirectory = path.dirname(targetFile);
+      mkdirp.sync(targetDirectory);
       imagemin([normalizedFile], targetDirectory, {
         use: [
           imageminOptipng(),
@@ -261,6 +259,10 @@ async function execute() {
           }),
           imageminGifsicle(),
         ],
+      }).catch(error => {
+        // if image compression fail, just copy it as it is
+        console.error(error);
+        fs.copySync(normalizedFile, targetFile);
       });
     } else if (!fs.lstatSync(normalizedFile).isDirectory()) {
       const parts = normalizedFile.split(`${sep}static${sep}`);