Fix file path handling on Windows

Co-authored-by: Josh Faigan <[email protected]>

Author: aswamy

.changeset/khaki-hornets-care.md

@@ -0,0 +1,5 @@
+---
+'@shopify/theme-check-node': patch
+---
+
+[Bug fix] Fix file URI handling for Windows platforms

packages/theme-check-node/src/index.ts

@@ -26,6 +26,7 @@ import glob = require('glob');
 import { autofix } from './autofix';
 import { findConfigPath, loadConfig as resolveConfig } from './config';
 import { NodeFileSystem } from './NodeFileSystem';
+import { fileURLToPath } from 'node:url';
 
 const asyncGlob = promisify(glob);
 
@@ -153,13 +154,29 @@ export async function getTheme(config: Config): Promise<Theme> {
   // as mentioned in the documentation of node-glob
 
   // the path is normalised and '\' are replaced with '/' and then passed to the glob function
-  const normalizedGlob = path
-    .normalize(path.join(config.rootUri.replace(/^file:/, ''), '**/*.{liquid,json}'))
-    .replace(/\\/g, '/');
-  const paths = await asyncGlob(normalizedGlob).then((result) =>
+  let normalizedGlob = getThemeFilesPathPattern(config.rootUri);
+
+  const paths = await asyncGlob(normalizedGlob, {absolute: true}).then((result) =>
     // Global ignored paths should not be part of the theme
     result.filter((filePath) => !isIgnored(filePath, config)),
   );
   const sourceCodes = await Promise.all(paths.map(toSourceCode));
   return sourceCodes.filter((x): x is LiquidSourceCode | JSONSourceCode => x !== undefined);
 }
+
+function getThemeFilesPathPattern(rootUri: string) {
+  let normalizedGlob = path
+    .normalize(path.join(fileURLToPath(rootUri), '**/*.{liquid,json}'))
+    .replace(/\\/g, '/');
+
+  // The glob is always an absoluate path, so windows paths should always
+  // start with a drive letter (with few exceptions we can ignore).
+  // More info: https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats
+  //
+  // If an absoluate path starts with a slash on Windows, we strip it
+  if (process.platform === 'win32' && normalizedGlob.match(/^\/[a-zA-Z]:/)) {
+    normalizedGlob = normalizedGlob.slice(1);
+  }
+
+  return normalizedGlob;
+}