fixes; add VimError class

src/cmd_line/commands/quit.ts

@@ -1,6 +1,7 @@
 import vscode = require('vscode');
 
 import node = require('../node');
+import error = require('../../error');
 
 export interface QuitCommandArguments extends node.CommandArgs {
 	bang?: boolean;
@@ -33,7 +34,7 @@ export class QuitCommand extends node.CommandBase {
 		// See https://github.com/Microsoft/vscode/issues/723
 		if ((this.activeTextEditor.document.isDirty || this.activeTextEditor.document.isUntitled)
 			&& !this.arguments.bang) {
-				throw new Error("unsaved changes");
+				throw error.VimError.fromCode(error.ErrorCode.E37);
 		}
 
 		vscode.commands.executeCommand('workbench.action.closeActiveEditor');

src/cmd_line/commands/write.ts

@@ -1,10 +1,9 @@
 // XXX: use graceful-fs ??
 import fs = require('fs');
 
-import vscode = require('vscode');
-
 import node = require('../node');
 import util = require('../../util');
+import error = require('../../error');
 
 export interface WriteCommandArguments extends node.CommandArgs {
 	opt? : string;
@@ -35,40 +34,44 @@ export class WriteCommand extends node.CommandBase {
 	}
 
 	execute() : void {
-		if (this._arguments.opt) {
+		if (this.arguments.opt) {
 			util.showError("Not implemented.");
 			return;
-		} else if (this._arguments.file) {
+		} else if (this.arguments.file) {
 			util.showError("Not implemented.");
 			return;
-		} else if (this._arguments.append) {
+		} else if (this.arguments.append) {
 			util.showError("Not implemented.");
 			return;
-		} else if (this._arguments.cmd) {
+		} else if (this.arguments.cmd) {
 			util.showError("Not implemented.");
 			return;
 		}
+
+		if (this.activeTextEditor.document.isUntitled) {
+			throw error.VimError.fromCode(error.ErrorCode.E32);
+		}		
 
 		fs.access(this.activeTextEditor.document.fileName, fs.W_OK, (accessErr) => {
 			if (accessErr) {
-				if (this._arguments.bang) {
+				if (this.arguments.bang) {
 					fs.chmod(this.activeTextEditor.document.fileName, 666, (e) => {
 						if (e) {
 							util.showError(e.message);
 						} else {
-							this.save(this.activeTextEditor);
+							this.save();
 						}
 					});
 				} else {
 					util.showError(accessErr.message);
 				}
 			} else {
-				this.save(this.activeTextEditor);
+				this.save();
 			}
 		});
 	}
 
-	private save(textEditor : vscode.TextEditor) {
+	private save() {		
 		this.activeTextEditor.document.save().then(
 			(ok) => {
 				if (ok) {

src/cmd_line/main.ts

@@ -4,6 +4,11 @@ import * as util from "../util";
 
 // Shows the vim command line.
 export function showCmdLine(initialText = "") {
+	if (!vscode.window.activeTextEditor) {
+		util.showInfo("No active document.");
+		return;
+	}
+
 	const options : vscode.InputBoxOptions = {
 		prompt: "Vim command line",
 		value: initialText
@@ -15,7 +20,7 @@ export function showCmdLine(initialText = "") {
 }
 
 function runCmdLine(s : string) : void {
-	if (!(s || s.trim())) {
+	if (!(s && s.trim())) {
 		return;
 	}
 
@@ -33,6 +38,13 @@ function runCmdLine(s : string) : void {
 	try {
 		cmd.execute(vscode.window.activeTextEditor);
 	} catch (e) {
-		util.showError(e);
+		try {
+			e.display();
+			return;
+		} catch (ee) {
+			// ignore
+		}
+
+		util.showError(e);	
 	}
 }

src/error.ts

@@ -0,0 +1,52 @@
+import * as util from "./util";
+
+interface VimErrors {
+	[index: number] : string;
+}
+
+export enum ErrorCode {
+	E37 = 37,
+	E32 = 32
+}
+
+const errors : VimErrors = {
+	32: "No file name",
+	37: "No write since last change (add ! to override)"
+};
+
+
+export class VimError extends Error {
+
+	private _code : number;
+	private _message : string;
+
+	constructor(code : number, message : string) {
+		super();
+		this._code = code;
+		this._message = message;
+	}
+
+	static fromCode(code : ErrorCode) : VimError {
+		if (errors[code]) {
+			return new VimError(code, errors[code]);
+		}
+
+		throw new Error("unknown error code: " + code);
+	}
+
+	get code() : number {
+		return this._code;
+	}
+
+	get message() : string {
+		return this._message;
+	}
+
+	display() : void {
+		util.showError(this.toString());
+	}
+
+	toString() : string {
+		return "E" + this.code.toString() + ": " + this.message;
+	}
+}