fix: view_range [start, -1] drops the last line in the Claude memory tool (#1043)

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

packages/tools/src/claude-memory.test.ts

@@ -0,0 +1,85 @@
+import { beforeEach, describe, expect, it, vi } from "vitest"
+
+// Mock the Supermemory SDK so the Claude memory tool's `view`/`readFile` path
+// can be exercised deterministically without any network access. We only need
+// `search.execute` to return a single document with known multi-line content.
+const searchExecute = vi.fn()
+
+vi.mock("supermemory", () => {
+	return {
+		default: class MockSupermemory {
+			search = { execute: searchExecute }
+			add = vi.fn()
+			memories = { forget: vi.fn() }
+		},
+	}
+})
+
+import { ClaudeMemoryTool } from "./claude-memory"
+
+const FILE_PATH = "/memories/notes.txt"
+// 5 distinct lines so an off-by-one at either end is observable.
+const FILE_CONTENT = "line1\nline2\nline3\nline4\nline5"
+
+function mockDocument(content: string) {
+	// `readFile` matches by `documentId === normalizePathToCustomId(path)`.
+	// normalizePathToCustomId("/memories/notes.txt") -> "memories_notes_txt"
+	searchExecute.mockResolvedValue({
+		results: [{ documentId: "memories_notes_txt", content }],
+	})
+}
+
+describe("ClaudeMemoryTool view_range", () => {
+	let tool: ClaudeMemoryTool
+
+	beforeEach(() => {
+		searchExecute.mockReset()
+		mockDocument(FILE_CONTENT)
+		tool = new ClaudeMemoryTool("test-api-key")
+	})
+
+	it("returns the final line when end is the -1 'to end of file' sentinel", async () => {
+		// Anthropic's text-editor / memory tool convention: an end of -1 means
+		// "read to the end of the file". The whole file must come back.
+		const result = await tool.handleCommand({
+			command: "view",
+			path: FILE_PATH,
+			view_range: [1, -1],
+		})
+
+		expect(result.success).toBe(true)
+		// Regression guard: the last line must not be dropped.
+		expect(result.content).toContain("line5")
+		// And every line should be present, in order.
+		for (const line of ["line1", "line2", "line3", "line4", "line5"]) {
+			expect(result.content).toContain(line)
+		}
+	})
+
+	it("reads from a start line to the end when end is -1", async () => {
+		const result = await tool.handleCommand({
+			command: "view",
+			path: FILE_PATH,
+			view_range: [3, -1],
+		})
+
+		expect(result.success).toBe(true)
+		expect(result.content).toContain("line3")
+		expect(result.content).toContain("line5")
+		expect(result.content).not.toContain("line2")
+	})
+
+	it("still honors explicit positive ranges", async () => {
+		const result = await tool.handleCommand({
+			command: "view",
+			path: FILE_PATH,
+			view_range: [2, 4],
+		})
+
+		expect(result.success).toBe(true)
+		expect(result.content).toContain("line2")
+		expect(result.content).toContain("line4")
+		expect(result.content).not.toContain("line1")
+		expect(result.content).not.toContain("line5")
+	})
+})

packages/tools/src/claude-memory.ts

@@ -283,7 +283,13 @@ export class ClaudeMemoryTool {
 			if (viewRange) {
 				const lines = content.split("\n")
 				const [startLine, endLine] = viewRange
-				const selectedLines = lines.slice(startLine - 1, endLine)
+				// `endLine === -1` is the documented sentinel for "read to the end
+				// of the file" (same convention as Anthropic's text-editor tool).
+				// Passing it straight to Array.slice would be interpreted as a
+				// from-the-end index and silently drop the final line, so map any
+				// negative end to the array length.
+				const sliceEnd = endLine < 0 ? lines.length : endLine
+				const selectedLines = lines.slice(startLine - 1, sliceEnd)
 
 				// Format with line numbers
 				const numberedLines = selectedLines.map(