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/bash.ts

@@ -13,7 +13,7 @@ export const bashTool: AgentTool<typeof bashSchema> = {
 		"Execute a bash command in the current working directory. Returns stdout and stderr. Commands run with a 30 second timeout.",
 	parameters: bashSchema,
 	execute: async (_toolCallId: string, { command }: { command: string }, signal?: AbortSignal) => {
-		return new Promise((resolve) => {
+		return new Promise((resolve, reject) => {
 			const child = spawn("sh", ["-c", command], {
 				detached: true,
 				stdio: ["ignore", "pipe", "pipe"],
@@ -65,10 +65,9 @@ export const bashTool: AgentTool<typeof bashSchema> = {
 						if (output) output += "\n";
 						output += stderr;
 					}
-					resolve({
-						output: output || "(no output)",
-						details: undefined,
-					});
+					if (output) output += "\n\n";
+					output += "Command aborted";
+					reject(new Error(output));
 					return;
 				}
 
@@ -81,10 +80,7 @@ export const bashTool: AgentTool<typeof bashSchema> = {
 					}
 					if (output) output += "\n\n";
 					output += "Command timed out after 30 seconds";
-					resolve({
-						output,
-						details: undefined,
-					});
+					reject(new Error(output));
 					return;
 				}
 
@@ -97,10 +93,7 @@ export const bashTool: AgentTool<typeof bashSchema> = {
 
 				if (code !== 0 && code !== null) {
 					if (output) output += "\n\n";
-					resolve({
-						output: `${output}Command exited with code ${code}`,
-						details: undefined,
-					});
+					reject(new Error(`${output}Command exited with code ${code}`));
 				} else {
 					resolve({ output: output || "(no output)", details: undefined });
 				}

packages/coding-agent/src/tools/edit.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, writeFileSync } 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 editSchema = Type.Object({
 	path: Type.String({ description: "Path to the file to edit (relative or absolute)" }),
 	oldText: Type.String({ description: "Exact text to find and replace (must match exactly)" }),
@@ -19,43 +33,37 @@ export const editTool: AgentTool<typeof editSchema> = {
 		_toolCallId: string,
 		{ path, oldText, newText }: { path: string; oldText: string; newText: 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");
-
-			// Check if old text exists
-			if (!content.includes(oldText)) {
-				return {
-					output: `Error: Could not find the exact text in ${path}. The old text must match exactly including all whitespace and newlines.`,
-					details: undefined,
-				};
-			}
-
-			// Count occurrences
-			const occurrences = content.split(oldText).length - 1;
-
-			if (occurrences > 1) {
-				return {
-					output: `Error: Found ${occurrences} occurrences of the text in ${path}. The text must be unique. Please provide more context to make it unique.`,
-					details: undefined,
-				};
-			}
-
-			// Perform replacement
-			const newContent = content.replace(oldText, newText);
-			writeFileSync(absolutePath, newContent, "utf-8");
-
-			return {
-				output: `Successfully replaced text in ${path}. Changed ${oldText.length} characters to ${newText.length} characters.`,
-				details: undefined,
-			};
-		} catch (error: any) {
-			return { output: `Error editing file: ${error.message}`, details: undefined };
+		if (!existsSync(absolutePath)) {
+			throw new Error(`File not found: ${path}`);
 		}
+
+		const content = readFileSync(absolutePath, "utf-8");
+
+		// Check if old text exists
+		if (!content.includes(oldText)) {
+			throw new Error(
+				`Could not find the exact text in ${path}. The old text must match exactly including all whitespace and newlines.`,
+			);
+		}
+
+		// Count occurrences
+		const occurrences = content.split(oldText).length - 1;
+
+		if (occurrences > 1) {
+			throw new Error(
+				`Found ${occurrences} occurrences of the text in ${path}. The text must be unique. Please provide more context to make it unique.`,
+			);
+		}
+
+		// Perform replacement
+		const newContent = content.replace(oldText, newText);
+		writeFileSync(absolutePath, newContent, "utf-8");
+
+		return {
+			output: `Successfully replaced text in ${path}. Changed ${oldText.length} characters to ${newText.length} characters.`,
+			details: undefined,
+		};
 	},
 };

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 };
 	},
 };

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 };
 	},
 };