fix(coding-agent): fixed read tool streaming routing and result expansion behavior

- Updated event-controller read-tool streaming handling to wait for a parseable target before routing tool calls, avoiding early component binding for unresolved arguments.
- Allowed internal-URL read calls to bypass the regular read grouping path and fall through to direct tool execution.
- Adjusted read tool rendering to honor the computed `expanded` flag for completed output instead of forcing expanded output.

packages/coding-agent/src/modes/controllers/event-controller.ts

@@ -277,21 +277,26 @@ export class EventController {
 
 			for (const content of this.ctx.streamingMessage.content) {
 				if (content.type !== "toolCall") continue;
-				if (
-					content.name === "read" &&
-					readArgsHaveTarget(content.arguments) &&
-					!readArgsTargetInternalUrl(content.arguments)
-				) {
-					this.#trackReadToolCall(content.id, content.arguments);
-					const component = this.ctx.pendingTools.get(content.id);
-					if (component) {
-						component.updateArgs(content.arguments, content.id);
-					} else {
-						const group = this.#getReadGroup();
-						group.updateArgs(content.arguments, content.id);
-						this.ctx.pendingTools.set(content.id, group);
+				if (content.name === "read") {
+					if (!readArgsHaveTarget(content.arguments)) {
+						// Args still streaming — defer until path is parseable so we can route to the
+						// read group (regular files) vs ToolExecutionComponent (internal URLs).
+						// Creating either component now would lock the read into the wrong shape.
+						continue;
 					}
-					continue;
+					if (!readArgsTargetInternalUrl(content.arguments)) {
+						this.#trackReadToolCall(content.id, content.arguments);
+						const component = this.ctx.pendingTools.get(content.id);
+						if (component) {
+							component.updateArgs(content.arguments, content.id);
+						} else {
+							const group = this.#getReadGroup();
+							group.updateArgs(content.arguments, content.id);
+							this.ctx.pendingTools.set(content.id, group);
+						}
+						continue;
+					}
+					// Internal URL read falls through to ToolExecutionComponent below.
 				}
 
 				// Preserve the raw partial JSON for renderers that need to surface fields before the JSON object closes.

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

@@ -1378,10 +1378,7 @@ export function renderReadUrlResult(
 		const outputBlock = new CachedOutputBlock();
 		return {
 			render: (width: number) =>
-				outputBlock.render(
-					{ header, state: "error", sections: [{ lines: errorLines }], width },
-					uiTheme,
-				),
+				outputBlock.render({ header, state: "error", sections: [{ lines: errorLines }], width }, uiTheme),
 			invalidate: () => outputBlock.invalidate(),
 		};
 	}

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

@@ -2674,7 +2674,6 @@ export function parsePrUnifiedDiff(text: string): PrDiffPayload {
 	return { unified: text, files };
 }
 
-
 interface ParsedDiffHeaderToken {
 	value: string;
 	nextIndex: number;
@@ -2719,7 +2718,7 @@ function parseDiffQuotedEscape(text: string, slashIndex: number): ParsedDiffHead
 		case "v":
 			return { value: "\v", nextIndex: slashIndex + 2 };
 		case "\\":
-		case "\"":
+		case '"':
 			return { value: next, nextIndex: slashIndex + 2 };
 		default:
 			return { value: next, nextIndex: slashIndex + 2 };
@@ -2727,11 +2726,11 @@ function parseDiffQuotedEscape(text: string, slashIndex: number): ParsedDiffHead
 }
 
 function parseDiffQuotedToken(text: string, startIndex: number): ParsedDiffHeaderToken | undefined {
-	if (text.charAt(startIndex) !== "\"") return undefined;
+	if (text.charAt(startIndex) !== '"') return undefined;
 	let value = "";
 	for (let i = startIndex + 1; i < text.length; i += 1) {
 		const ch = text.charAt(i);
-		if (ch === "\"") return { value, nextIndex: i + 1 };
+		if (ch === '"') return { value, nextIndex: i + 1 };
 		if (ch !== "\\") {
 			value += ch;
 			continue;
@@ -2759,7 +2758,7 @@ function stripPrDiffPathPrefix(value: string, prefix: "a/" | "b/"): string | und
 
 function parsePrDiffHeaderPaths(header: string): { oldPath?: string; newPath?: string } {
 	const trail = header.slice("diff --git ".length);
-	if (trail.startsWith("\"")) {
+	if (trail.startsWith('"')) {
 		const oldToken = parseDiffQuotedToken(trail, 0);
 		if (!oldToken) return {};
 		const newToken = parseDiffHeaderToken(trail, oldToken.nextIndex);
@@ -2786,8 +2785,8 @@ function isPrDiffFileHeaderLine(line: string): boolean {
 		line === "+++ /dev/null" ||
 		line.startsWith("--- a/") ||
 		line.startsWith("+++ b/") ||
-		line.startsWith("--- \"a/") ||
-		line.startsWith("+++ \"b/")
+		line.startsWith('--- "a/') ||
+		line.startsWith('+++ "b/')
 	);
 }
 

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

@@ -1840,10 +1840,7 @@ export const readToolRenderer = {
 			const outputBlock = new CachedOutputBlock();
 			return {
 				render: (width: number) =>
-					outputBlock.render(
-						{ header, state: "error", sections: [{ lines: errorLines }], width },
-						uiTheme,
-					),
+					outputBlock.render({ header, state: "error", sections: [{ lines: errorLines }], width }, uiTheme),
 				invalidate: () => outputBlock.invalidate(),
 			};
 		}
@@ -1938,7 +1935,7 @@ export const readToolRenderer = {
 								title,
 								status: "complete",
 								output: warningLines.length > 0 ? warningLines.join("\n") : undefined,
-								expanded: true,
+								expanded,
 								width,
 							},
 							uiTheme,