Implement plugin API to get workspace folder by file URI

packages/plugin-ext/src/main/browser/workspace-main.ts

@@ -63,13 +63,13 @@ export class WorkspaceMainImpl implements WorkspaceMain {
 
     notifyWorkspaceFoldersChanged(): void {
         if (this.roots && this.roots.length) {
-            const folders = this.roots.map(root => {
+            const folders = this.roots.map((root: FileStat, index: number) => {
                 const uri = Uri.parse(root.uri);
                 const path = new Path(uri.path);
                 return {
                     uri: uri,
                     name: path.base,
-                    index: 0
+                    index: index
                 };
             });
 

packages/plugin-ext/src/plugin/plugin-context.ts

@@ -165,8 +165,8 @@ export function createAPIFactory(
                 return editors.onDidChangeTextEditorVisibleRanges(listener, thisArg, disposables);
             },
             async showTextDocument(documentArg: theia.TextDocument | Uri,
-                                   optionsArg?: theia.TextDocumentShowOptions | theia.ViewColumn,
-                                   preserveFocus?: boolean
+                optionsArg?: theia.TextDocumentShowOptions | theia.ViewColumn,
+                preserveFocus?: boolean
             ): Promise<theia.TextEditor> {
                 let documentOptions: theia.TextDocumentShowOptions | undefined;
                 const uri: Uri = documentArg instanceof Uri ? documentArg : documentArg.uri;
@@ -352,6 +352,9 @@ export function createAPIFactory(
             registerFileSystemProvider(scheme: string, provider: theia.FileSystemProvider, options?: { isCaseSensitive?: boolean, isReadonly?: boolean }): theia.Disposable {
                 // FIXME: to implement
                 return new Disposable(() => { });
+            },
+            getWorkspaceFolder(uri: Uri): theia.WorkspaceFolder | Uri | undefined {
+                return workspaceExt.getWorkspaceFolder(uri);
             }
         };
 

packages/plugin-ext/src/plugin/workspace.ts

@@ -169,4 +169,35 @@ export class WorkspaceExtImpl implements WorkspaceExt {
         return undefined;
     }
 
+    getWorkspaceFolder(uri: URI): theia.WorkspaceFolder | URI | undefined {
+        if (!this.folders || !this.folders.length) {
+            return undefined;
+        }
+
+        const resourcePath = uri.toString();
+
+        let workspaceFolder: theia.WorkspaceFolder | undefined;
+        for (let i = 0; i < this.folders.length; i++) {
+            const folder = this.folders[i];
+            const folderPath = folder.uri.toString();
+
+            if (resourcePath === folderPath) {
+                // return the input when the given uri is a workspace folder itself
+                return uri;
+            }
+
+            if (this.matchPaths(resourcePath, folderPath) && (!workspaceFolder || folderPath.length > workspaceFolder.uri.toString().length)) {
+                workspaceFolder = folder;
+            }
+        }
+        return workspaceFolder;
+    }
+
+    private matchPaths(resourcePath: string, folderPath: string): boolean {
+        const resourcePathCrumbs = resourcePath.split('/');
+        const folderPathCrumbs = folderPath.split('/');
+
+        return folderPathCrumbs.every((crumb, index) => crumb === resourcePathCrumbs[index]);
+    }
+
 }