lib: add UNC support to url.pathToFileURL()

Fixes: #34736 PR-URL: #34743 Reviewed-By: Guy Bedford <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Rich Trott <[email protected]>

Author: mceachen

lib/internal/url.js

@@ -27,6 +27,7 @@ const{getConstructorOf, removeColors } = require('internal/util');
 const{
 ERR_ARG_NOT_ITERABLE,
 ERR_INVALID_ARG_TYPE,
+ERR_INVALID_ARG_VALUE,
 ERR_INVALID_CALLBACK,
 ERR_INVALID_FILE_URL_HOST,
 ERR_INVALID_FILE_URL_PATH,
@@ -1366,27 +1367,54 @@ const backslashRegEx = /\\/g;
 constnewlineRegEx=/\n/g;
 constcarriageReturnRegEx=/\r/g;
 consttabRegEx=/\t/g;
+
+functionencodePathChars(filepath){
+if(filepath.includes('%'))
+filepath=filepath.replace(percentRegEx,'%25');
+// In posix, backslash is a valid character in paths:
+if(!isWindows&&filepath.includes('\\'))
+filepath=filepath.replace(backslashRegEx,'%5C');
+if(filepath.includes('\n'))
+filepath=filepath.replace(newlineRegEx,'%0A');
+if(filepath.includes('\r'))
+filepath=filepath.replace(carriageReturnRegEx,'%0D');
+if(filepath.includes('\t'))
+filepath=filepath.replace(tabRegEx,'%09');
+returnfilepath;
+}
+
 functionpathToFileURL(filepath){
-letresolved=path.resolve(filepath);
-// path.resolve strips trailing slashes so we must add them back
-constfilePathLast=filepath.charCodeAt(filepath.length-1);
-if((filePathLast===CHAR_FORWARD_SLASH||
-(isWindows&&filePathLast===CHAR_BACKWARD_SLASH))&&
-resolved[resolved.length-1]!==path.sep)
-resolved+='/';
 constoutURL=newURL('file://');
-if(resolved.includes('%'))
-resolved=resolved.replace(percentRegEx,'%25');
-// In posix, "/" is a valid character in paths
-if(!isWindows&&resolved.includes('\\'))
-resolved=resolved.replace(backslashRegEx,'%5C');
-if(resolved.includes('\n'))
-resolved=resolved.replace(newlineRegEx,'%0A');
-if(resolved.includes('\r'))
-resolved=resolved.replace(carriageReturnRegEx,'%0D');
-if(resolved.includes('\t'))
-resolved=resolved.replace(tabRegEx,'%09');
-outURL.pathname=resolved;
+if(isWindows&&filepath.startsWith('\\\\')){
+// UNC path format: \\server\share\resource
+constpaths=filepath.split('\\');
+if(paths.length<=3){
+thrownewERR_INVALID_ARG_VALUE(
+'filepath',
+filepath,
+'Missing UNC resource path'
+);
+}
+consthostname=paths[2];
+if(hostname.length===0){
+thrownewERR_INVALID_ARG_VALUE(
+'filepath',
+filepath,
+'Empty UNC servername'
+);
+}
+outURL.hostname=domainToASCII(hostname);
+outURL.pathname=encodePathChars(paths.slice(3).join('/'));
+}else{
+letresolved=path.resolve(filepath);
+// path.resolve strips trailing slashes so we must add them back
+constfilePathLast=filepath.charCodeAt(filepath.length-1);
+if((filePathLast===CHAR_FORWARD_SLASH||
+(isWindows&&filePathLast===CHAR_BACKWARD_SLASH))&&
+resolved[resolved.length-1]!==path.sep)
+resolved+='/';
+outURL.pathname=encodePathChars(resolved);
+}
 returnoutURL;
 }
 

test/parallel/test-url-fileurltopath.js

@@ -94,7 +94,9 @@ assert.throws(() => url.fileURLToPath('https://a/b/c'),{
 // Euro sign (BMP code point)
 {path: 'C:\\€',fileURL: 'file:///C:/%E2%82%AC'},
 // Rocket emoji (non-BMP code point)
-{path: 'C:\\🚀',fileURL: 'file:///C:/%F0%9F%9A%80'}
+{path: 'C:\\🚀',fileURL: 'file:///C:/%F0%9F%9A%80'},
+// UNC path (see https://docs.microsoft.com/en-us/archive/blogs/ie/file-uris-in-windows)
+{path: '\\\\nas\\My Docs\\File.doc',fileURL: 'file://nas/My%20Docs/File.doc'},
 ];
 }else{
 testCases=[

test/parallel/test-url-pathtofileurl.js

@@ -23,6 +23,26 @@ const url = require('url');
 assert.ok(fileURL.includes('%25'));
 }
 
+{
+if(isWindows){
+// UNC path: \\server\share\resource
+
+// Missing server:
+assert.throws(()=>url.pathToFileURL('\\\\\\no-server'),{
+code: 'ERR_INVALID_ARG_VALUE'
+});
+
+// Missing share or resource:
+assert.throws(()=>url.pathToFileURL('\\\\host'),{
+code: 'ERR_INVALID_ARG_VALUE'
+});
+}else{
+// UNC paths on posix are considered a single path that has backslashes:
+constfileURL=url.pathToFileURL('\\\\nas\\share\\path.txt').href;
+assert.match(fileURL,/file:\/\/.+%5C%5Cnas%5Cshare%5Cpath\.txt$/);
+}
+}
+
 {
 lettestCases;
 if(isWindows){
@@ -68,7 +88,9 @@ const url = require('url');
 // Euro sign (BMP code point)
 {path: 'C:\\€',expected: 'file:///C:/%E2%82%AC'},
 // Rocket emoji (non-BMP code point)
-{path: 'C:\\🚀',expected: 'file:///C:/%F0%9F%9A%80'}
+{path: 'C:\\🚀',expected: 'file:///C:/%F0%9F%9A%80'},
+// UNC path (see https://docs.microsoft.com/en-us/archive/blogs/ie/file-uris-in-windows)
+{path: '\\\\nas\\My Docs\\File.doc',expected: 'file://nas/My%20Docs/File.doc'}
 ];
 }else{
 testCases=[