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/read.ts

@@ -1,8 +1,22 @@
+import * as os from "node:os";
 import type { AgentTool } from "@mariozechner/pi-ai";
 import { Type } from "@sinclair/typebox";
 import { existsSync, readFileSync } from "fs";
 import { 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 readSchema = Type.Object({
 	path: Type.String({ description: "Path to the file to read (relative or absolute)" }),
 });
@@ -13,17 +27,13 @@ export const readTool: AgentTool<typeof readSchema> = {
 	description: "Read the contents of a file. Returns the full file content as text.",
 	parameters: readSchema,
 	execute: async (_toolCallId: string, { path }: { path: string }) => {
-		try {
-			const absolutePath = resolve(path);
+		const absolutePath = resolve(expandPath(path));
 
-			if (!existsSync(absolutePath)) {
-				return { output: `Error: File not found: ${path}`, details: undefined };
-			}
-
-			const content = readFileSync(absolutePath, "utf-8");
-			return { output: content, details: undefined };
-		} catch (error: any) {
-			return { output: `Error reading file: ${error.message}`, details: undefined };
+		if (!existsSync(absolutePath)) {
+			throw new Error(`File not found: ${path}`);
 		}
+
+		const content = readFileSync(absolutePath, "utf-8");
+		return { output: content, details: undefined };
 	},
 };