improve error handling in variableResolver

src/vs/workbench/services/configurationResolver/node/variableResolver.ts

@@ -72,6 +72,7 @@ export class VariableResolver {
 			}
 
 			switch (variable) {
+
 				case 'env':
 					if (argument) {
 						if (isWindows) {
@@ -84,104 +85,112 @@ export class VariableResolver {
 						// For `env` we should do the same as a normal shell does - evaluates missing envs to an empty string #46436
 						return '';
 					}
-					throw new Error(localize('missingEnvVarName', "'{0}' can not be resolved because no environment variable is given.", match));
+					throw new Error(localize('missingEnvVarName', "'{0}' can not be resolved because no environment variable name is given.", match));
 
 				case 'config':
 					if (argument) {
 						const config = this.accessor.getConfigurationValue(folderUri, argument);
-						if (!types.isUndefinedOrNull(config) && !types.isObject(config)) {
-							return config;
+						if (types.isUndefinedOrNull(config)) {
+							throw new Error(localize('configNotFound', "'{0}' can not be resolved because setting '{1}' not found.", match, argument));
+						}
+						if (types.isObject(config)) {
+							throw new Error(localize('configNoString', "'{0}' can not be resolved because '{1}' is a structured value.", match, argument));
 						}
-						throw new Error(localize('configNoString', "'{0}' can not be resolved because '{1}' is a structured value.", match, argument));
+						return config;
 					}
 					throw new Error(localize('missingConfigName', "'{0}' can not be resolved because no settings name is given.", match));
 
 				default: {
 
-					if (argument) {
-						const folder = this.accessor.getFolderUri(argument);
-						if (folder) {
-							folderUri = folder;
-						}
-					}
-
+					// common error handling for all variables that require an open folder and accept a folder name argument
 					switch (variable) {
 						case 'workspaceRoot':
 						case 'workspaceFolder':
-							if (folderUri) {
-								return normalizeDriveLetter(folderUri.fsPath);
+						case 'workspaceRootFolderName':
+						case 'workspaceFolderBasename':
+						case 'relativeFile':
+							if (argument) {
+								const folder = this.accessor.getFolderUri(argument);
+								if (folder) {
+									folderUri = folder;
+								} else {
+									throw new Error(localize('canNotFindFolder', "'{0}' can not be resolved. No such folder '{1}'.", match, argument));
+								}
 							}
-							if (this.accessor.getWorkspaceFolderCount() > 1) {
-								throw new Error(localize('canNotResolveWorkspaceFolderMultiRoot', "'{0}' can not be resolved in a multi folder workspace. Scope this variable using ':' and a workspace folder name.", match));
+							if (!folderUri) {
+								if (this.accessor.getWorkspaceFolderCount() > 1) {
+									throw new Error(localize('canNotResolveWorkspaceFolderMultiRoot', "'{0}' can not be resolved in a multi folder workspace. Scope this variable using ':' and a workspace folder name.", match));
+								}
+								throw new Error(localize('canNotResolveWorkspaceFolder', "'{0}' can not be resolved. Please open a folder.", match));
 							}
-							throw new Error(localize('canNotResolveWorkspaceFolder', "'{0}' can not be resolved. Please open a folder.", match));
+							break;
+						default:
+							break;
+					}
+
+					// common error handling for all variables that require an open file
+					switch (variable) {
+						case 'file':
+						case 'relativeFile':
+						case 'fileDirname':
+						case 'fileExtname':
+						case 'fileBasename':
+						case 'fileBasenameNoExtension':
+							if (!filePath) {
+								throw new Error(localize('canNotResolveFile', "'{0}' can not be resolved. Please open an editor.", match));
+							}
+							break;
+						default:
+							break;
+					}
+
+					switch (variable) {
+						case 'workspaceRoot':
+						case 'workspaceFolder':
+							return normalizeDriveLetter(folderUri.fsPath);
 
 						case 'cwd':
 							return folderUri ? normalizeDriveLetter(folderUri.fsPath) : process.cwd();
 
 						case 'workspaceRootFolderName':
 						case 'workspaceFolderBasename':
-							if (folderUri) {
-								return paths.basename(folderUri.fsPath);
-							}
-							if (this.accessor.getWorkspaceFolderCount() > 1) {
-								throw new Error(localize('canNotResolveFolderBasenameMultiRoot', "'{0}' can not be resolved in a multi folder workspace. Scope this variable using ':' and a workspace folder name.", match));
-							}
-							throw new Error(localize('canNotResolveFolderBasename', "'{0}' can not be resolved. Please open a folder.", match));
+							return paths.basename(folderUri.fsPath);
 
 						case 'lineNumber':
 							const lineNumber = this.accessor.getLineNumber();
 							if (lineNumber) {
 								return lineNumber;
 							}
-							throw new Error(localize('canNotResolveLineNumber', "'{0}' can not be resolved. Please open an editor.", match));
+							throw new Error(localize('canNotResolveLineNumber', "'{0}' can not be resolved. Make sure to have a line selected in the active editor.", match));
 
 						case 'selectedText':
 							const selectedText = this.accessor.getSelectedText();
 							if (selectedText) {
 								return selectedText;
 							}
-							throw new Error(localize('canNotResolveSelectedText', "'{0}' can not be resolved. Please open an editor and select some text.", match));
+							throw new Error(localize('canNotResolveSelectedText', "'{0}' can not be resolved. Make sure to have some text selected in the active editor.", match));
 
 						case 'file':
-							if (filePath) {
-								return filePath;
-							}
-							throw new Error(localize('canNotResolveFile', "'{0}' can not be resolved. Please open an editor.", match));
+							return filePath;
 
 						case 'relativeFile':
-							if (folderUri && filePath) {
+							if (folderUri) {
 								return paths.normalize(relative(folderUri.fsPath, filePath));
 							}
-							if (filePath) {
-								return filePath;
-							}
-							throw new Error(localize('canNotResolveRelativeFile', "'{0}' can not be resolved. Please open an editor.", match));
+							return filePath;
 
 						case 'fileDirname':
-							if (filePath) {
-								return paths.dirname(filePath);
-							}
-							throw new Error(localize('canNotResolveFileDirname', "'{0}' can not be resolved. Please open an editor.", match));
+							return paths.dirname(filePath);
 
 						case 'fileExtname':
-							if (filePath) {
-								return paths.extname(filePath);
-							}
-							throw new Error(localize('canNotResolveFileExtname', "'{0}' can not be resolved. Please open an editor.", match));
+							return paths.extname(filePath);
 
 						case 'fileBasename':
-							if (filePath) {
-								return paths.basename(filePath);
-							}
-							throw new Error(localize('canNotResolveFileBasename', "'{0}' can not be resolved. Please open an editor.", match));
+							return paths.basename(filePath);
 
 						case 'fileBasenameNoExtension':
-							if (filePath) {
-								const basename = paths.basename(filePath);
-								return basename.slice(0, basename.length - paths.extname(basename).length);
-							}
-							throw new Error(localize('canNotResolveFileBasenameNoExtension', "'{0}' can not be resolved. Please open an editor.", match));
+							const basename = paths.basename(filePath);
+							return basename.slice(0, basename.length - paths.extname(basename).length);
 
 						case 'execPath':
 							return this.accessor.getEnvironmentService('execPath');