fix: avoid XML false positives for <editor>/<editable> tags

hannesrudolph · hannesrudolph · commit d7d8dcea29d0 · 2026-02-07T19:57:08.000-07:00
diff --git a/src/core/assistant-message/__tests__/presentAssistantMessage-unknown-tool.spec.ts b/src/core/assistant-message/__tests__/presentAssistantMessage-unknown-tool.spec.ts
@@ -242,4 +242,54 @@ describe("presentAssistantMessage - Unknown Tool Handling", () => {
 		expect(toolResult.is_error).toBe(true)
 		expect(toolResult.content).toContain("due to user rejecting a previous tool")
 	})
+
+	it("should not treat <editor> as XML tool markup", async () => {
+		mockTask.assistantMessageContent = [
+			{
+				type: "text",
+				content: "Please open the <editor> panel and continue.",
+				partial: false,
+			},
+		]
+
+		await presentAssistantMessage(mockTask)
+
+		expect(mockTask.say).toHaveBeenCalledWith(
+			"text",
+			"Please open the <editor> panel and continue.",
+			undefined,
+			false,
+		)
+		expect(mockTask.say).not.toHaveBeenCalledWith(
+			"error",
+			expect.stringContaining("XML tool calls are no longer supported"),
+		)
+		expect(mockTask.didAlreadyUseTool).toBe(false)
+		expect(mockTask.consecutiveMistakeCount).toBe(0)
+	})
+
+	it("should not treat <editable> as XML tool markup", async () => {
+		mockTask.assistantMessageContent = [
+			{
+				type: "text",
+				content: "Use an <editable> region in the docs example.",
+				partial: false,
+			},
+		]
+
+		await presentAssistantMessage(mockTask)
+
+		expect(mockTask.say).toHaveBeenCalledWith(
+			"text",
+			"Use an <editable> region in the docs example.",
+			undefined,
+			false,
+		)
+		expect(mockTask.say).not.toHaveBeenCalledWith(
+			"error",
+			expect.stringContaining("XML tool calls are no longer supported"),
+		)
+		expect(mockTask.didAlreadyUseTool).toBe(false)
+		expect(mockTask.consecutiveMistakeCount).toBe(0)
+	})
 })
diff --git a/src/core/assistant-message/presentAssistantMessage.ts b/src/core/assistant-message/presentAssistantMessage.ts
@@ -1048,6 +1048,25 @@ function containsXmlToolMarkup(text: string): boolean {
 	// Avoid regex so we don't keep legacy XML parsing artifacts around.
 	// Note: This is a best-effort safeguard; tool_use blocks without an id are rejected elsewhere.
 
+	const isTagBoundary = (char: string | undefined): boolean => {
+		if (char === undefined) {
+			return true
+		}
+		return char === ">" || char === "/" || char === " " || char === "\n" || char === "\r" || char === "\t"
+	}
+
+	const hasTagReference = (haystack: string, prefix: string): boolean => {
+		let index = haystack.indexOf(prefix)
+		while (index !== -1) {
+			const nextChar = haystack[index + prefix.length]
+			if (isTagBoundary(nextChar)) {
+				return true
+			}
+			index = haystack.indexOf(prefix, index + 1)
+		}
+		return false
+	}
+
 	// First, strip out content inside markdown code fences to avoid false positives
 	// when users paste documentation or examples containing tool tag references.
 	// This handles both fenced code blocks (```) and inline code (`).
@@ -1085,5 +1104,5 @@ function containsXmlToolMarkup(text: string): boolean {
 		"write_to_file",
 	] as const
 
-	return toolNames.some((name) => lower.includes(`<${name}`) || lower.includes(`</${name}`))
+	return toolNames.some((name) => hasTagReference(lower, `<${name}`) || hasTagReference(lower, `</${name}`))
 }
