From 4b27acfcaeffa972921abb1f77333cc874b4642e Mon Sep 17 00:00:00 2001
From: Ben Stull <ben.stull@wiggleverse.org>
Date: Wed, 10 Jun 2026 10:01:49 -0700
Subject: [PATCH] F3 SLICE-4: persistence/re-anchor/orphan decision-logic tests
 (INV-1/INV-6) (#6)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 test/attributionPersistence.test.ts | 54 +++++++++++++++++++++++++++++
 test/attributionTracker.test.ts     | 26 ++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 test/attributionPersistence.test.ts

diff --git a/test/attributionPersistence.test.ts b/test/attributionPersistence.test.ts
new file mode 100644
index 0000000..76670e1
--- /dev/null
+++ b/test/attributionPersistence.test.ts
@@ -0,0 +1,54 @@
+import { describe, it, expect } from "vitest";
+import { buildFingerprint, resolve } from "../src/anchorer";
+import { applyChange, type LiveSpan } from "../src/attributionTracker";
+import type { Provenance } from "../src/model";
+
+const HUMAN: Provenance = { kind: "human", id: "ben" };
+const DOC = "intro\nClaude wrote this sentence here.\noutro\n";
+
+function liveSpan(): LiveSpan {
+  const start = DOC.indexOf("Claude wrote this sentence");
+  return {
+    id: "at_1", start, end: start + "Claude wrote this sentence".length,
+    author: { kind: "agent", id: "claude", agent: { sdk: "@cline/sdk", model: "sonnet", sessionId: "r1" } },
+    createdAt: "2026-06-10T00:00:00.000Z",
+  };
+}
+
+describe("attribution persistence decision logic (SLICE-4, spec §6.5 PUC-4)", () => {
+  it("save → reload: fingerprint built from the live span resolves to the same range", () => {
+    const s = liveSpan();
+    const fp = buildFingerprint(DOC, { start: s.start, end: s.end });
+    expect(resolve(DOC, fp)).toEqual({ start: s.start, end: s.end });
+  });
+
+  it("external edit above: fingerprint re-resolves at the moved range", () => {
+    const s = liveSpan();
+    const fp = buildFingerprint(DOC, { start: s.start, end: s.end });
+    const edited = "a new line\n" + DOC;
+    const moved = edited.indexOf("Claude wrote this sentence");
+    expect(resolve(edited, fp)).toEqual({ start: moved, end: moved + (s.end - s.start) });
+  });
+
+  it("anchored text mangled: orphaned, never guessed (INV-1/INV-6)", () => {
+    const s = liveSpan();
+    const fp = buildFingerprint(DOC, { start: s.start, end: s.end });
+    const mangled = DOC.replace("Claude wrote this sentence", "Someone rewrote everything");
+    expect(resolve(mangled, fp)).toBe("orphaned");
+  });
+
+  it("in-session edits keep the live span fingerprint-able (tracker → anchorer round trip)", () => {
+    let spans = [liveSpan()];
+    let doc = DOC;
+    const insertAt = DOC.indexOf("intro") + "intro".length;
+    const inserted = " (note)";
+    doc = doc.slice(0, insertAt) + inserted + doc.slice(insertAt);
+    spans = applyChange(spans, { start: insertAt, end: insertAt, newLength: inserted.length }, HUMAN, {
+      newId: () => "n1", now: () => "2026-06-10T01:00:00.000Z",
+    });
+    const agent = spans.find((x) => x.author.kind === "agent")!;
+    expect(doc.slice(agent.start, agent.end)).toBe("Claude wrote this sentence");
+    const fp = buildFingerprint(doc, { start: agent.start, end: agent.end });
+    expect(resolve(doc, fp)).toEqual({ start: agent.start, end: agent.end });
+  });
+});
diff --git a/test/attributionTracker.test.ts b/test/attributionTracker.test.ts
index c590a8e..de0c9e8 100644
--- a/test/attributionTracker.test.ts
+++ b/test/attributionTracker.test.ts
@@ -125,3 +125,29 @@ describe("coalesce", () => {
     expect(coalesce([span("a", 5, 5, HUMAN)])).toEqual([]);
   });
 });
+
+describe("edge probes (post-review)", () => {
+  it("applyChange does not mutate its input array or spans", () => {
+    const input = [span("a", 0, 10, AGENT)];
+    const snapshot = JSON.parse(JSON.stringify(input));
+    applyChange(input, { start: 2, end: 4, newLength: 1 }, HUMAN, ctx());
+    expect(input).toEqual(snapshot);
+  });
+  it("an edit swallowing a whole middle span across three spans removes only it", () => {
+    // Deletion [3,9): a → [0,3); b swallowed; c's remainder [9,12) shifts -6 to
+    // [3,6). The two surviving HUMAN spans are adjacent at 3 with the same
+    // (undefined) turnId, so coalesce merges them into ONE span — only the
+    // agent-authored middle span's characters are gone (INV-6/INV-7).
+    const r = applyChange(
+      [span("a", 0, 4, HUMAN), span("b", 4, 8, AGENT), span("c", 8, 12, HUMAN)],
+      { start: 3, end: 9, newLength: 0 }, HUMAN, ctx(),
+    );
+    expect(ranges(r)).toEqual([[0, 6]]);
+    expect(authors(r)).toEqual(["human"]);
+  });
+  it("a replacement exactly covering a span replaces it with the editor's span", () => {
+    const r = applyChange([span("a", 4, 8, AGENT)], { start: 4, end: 8, newLength: 4 }, HUMAN, ctx());
+    expect(ranges(r)).toEqual([[4, 8]]);
+    expect(authors(r)).toEqual(["human"]);
+  });
+});