adding relFile to support substituting the path tot he current open file realtive to cwd

extensions/vscode-colorize-tests/.vscode/tasks.json

@@ -1,6 +1,7 @@
 // Available variables which can be used inside of strings.
 // ${workspaceRoot}: the root folder of the team
 // ${file}: the current opened file
+// ${relFile}: the current opened file relative to cwd
 // ${fileBasename}: the current opened file's basename
 // ${fileDirname}: the current opened file's dirname
 // ${fileExtname}: the current opened file's extension

src/vs/workbench/parts/lib/node/systemVariables.ts

@@ -48,6 +48,10 @@ export class SystemVariables extends AbstractSystemVariables {
 		return this.getFilePath();
 	}
 
+	public get relFile(): string {
+		return Paths.relative(this.cwd, this.file);
+	}
+
 	public get fileBasename(): string {
 		return Paths.basename(this.getFilePath());
 	}