Improve tool execution rendering and error handling

- Show tool execution components immediately when tool calls appear in streaming
- Update components with streaming arguments as they come in
- Handle incomplete/partial arguments gracefully with optional chaining
- Fix error handling: tools now throw exceptions instead of returning error messages
- Fix bash abort handling to properly reject on abort/timeout
- Clean up error display

packages/coding-agent/src/tools/write.ts

@@ -1,8 +1,22 @@
+import * as os from "node:os";
 import type { AgentTool } from "@mariozechner/pi-ai";
 import { Type } from "@sinclair/typebox";
 import { mkdirSync, writeFileSync } from "fs";
 import { dirname, resolve } from "path";
 
+/**
+ * Expand ~ to home directory
+ */
+function expandPath(filePath: string): string {
+	if (filePath === "~") {
+		return os.homedir();
+	}
+	if (filePath.startsWith("~/")) {
+		return os.homedir() + filePath.slice(1);
+	}
+	return filePath;
+}
+
 const writeSchema = Type.Object({
 	path: Type.String({ description: "Path to the file to write (relative or absolute)" }),
 	content: Type.String({ description: "Content to write to the file" }),
@@ -15,17 +29,13 @@ export const writeTool: AgentTool<typeof writeSchema> = {
 		"Write content to a file. Creates the file if it doesn't exist, overwrites if it does. Automatically creates parent directories.",
 	parameters: writeSchema,
 	execute: async (_toolCallId: string, { path, content }: { path: string; content: string }) => {
-		try {
-			const absolutePath = resolve(path);
-			const dir = dirname(absolutePath);
+		const absolutePath = resolve(expandPath(path));
+		const dir = dirname(absolutePath);
 
-			// Create parent directories if needed
-			mkdirSync(dir, { recursive: true });
+		// Create parent directories if needed
+		mkdirSync(dir, { recursive: true });
 
-			writeFileSync(absolutePath, content, "utf-8");
-			return { output: `Successfully wrote ${content.length} bytes to ${path}`, details: undefined };
-		} catch (error: any) {
-			return { output: `Error writing file: ${error.message}`, details: undefined };
-		}
+		writeFileSync(absolutePath, content, "utf-8");
+		return { output: `Successfully wrote ${content.length} bytes to ${path}`, details: undefined };
 	},
 };