feat(git-sync): three-way body merge using the last-synced base (no edit loss)

Upgrades the 2-way body merge to a real diff3 three-way merge (review #5), so a
block ONLY the human changed is KEPT when git changed a DIFFERENT block — the
2-way merge would revert it to git's stale version.

Engine: the push update loop reads the last-synced pre-image
(`git.showFileAtRef(refs/docmost/last-pushed, path)`) and passes it as the
optional `baseMarkdown` to `client.importPageMarkdown` (the common ancestor).

Server: gitmost-datasource converts base+incoming, and writeBody runs a block-
level diff3 (new three-way-merge.ts `diff3Plan`): live-only change -> keep live,
git-only change -> take git, both-changed -> git wins (conflict policy), inserts/
deletes from either side preserved. Without a base (createPage) it falls back to
the 2-way merge. Crash-safety unchanged (docs built before the connection opens).

Tests: three-way-merge.spec.ts (14 — every diff3 case incl. the cross-block
preservation and conflict policy), yjs-body-merge 3-way (real Y.Docs: human's
block instance preserved while git's block is applied), plus an engine test that
the base is forwarded from showFileAtRef. Existing push assertions updated for the
new base arg. git-sync 589 pass; server merge/datasource/gate 62 pass; typecheck
clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/server/src/integrations/git-sync/services/gitmost-datasource.service.ts

@@ -14,7 +14,7 @@ import { KyselyDB } from '@docmost/db/types/kysely.types';
 import { PageService } from '../../../core/page/services/page.service';
 import { CollaborationGateway } from '../../../collaboration/collaboration.gateway';
 import { tiptapExtensions } from '../../../collaboration/collaboration.util';
-import { mergeXmlFragments } from './yjs-body-merge';
+import { mergeXmlFragments, mergeXmlFragments3Way } from './yjs-body-merge';
 import { AuthProvenanceData } from '../../../common/decorators/auth-provenance.decorator';
 
 /**
@@ -74,8 +74,8 @@ export class GitmostDataSourceService {
       listSpaceTree: (spaceId, rootPageId) =>
         this.listSpaceTree(ctx, spaceId, rootPageId),
       getPageJson: (pageId) => this.getPageJson(ctx, pageId),
-      importPageMarkdown: (pageId, fullMarkdown) =>
-        this.importPageMarkdown(ctx, pageId, fullMarkdown),
+      importPageMarkdown: (pageId, fullMarkdown, baseMarkdown) =>
+        this.importPageMarkdown(ctx, pageId, fullMarkdown, baseMarkdown),
       createPage: (title, content, spaceId, parentPageId) =>
         this.createPage(ctx, title, content, spaceId, parentPageId),
       deletePage: (pageId) => this.deletePage(ctx, pageId),
@@ -164,18 +164,29 @@ export class GitmostDataSourceService {
   // --- writes (push) --------------------------------------------------------
 
   /**
-   * Replace a page's body from a self-contained markdown file: parse the meta+
-   * body envelope, convert the body to ProseMirror, then write it through collab
-   * (§3.3). Returns the fresh page's `updatedAt` for the loop-guard.
+   * Merge a page's body from a self-contained markdown file: parse the meta+body
+   * envelope, convert the body to ProseMirror, then merge it through collab
+   * (§3.3). When `baseMarkdown` (the last-synced version of the file) is given,
+   * the body write is a THREE-WAY merge against the live doc so concurrent human
+   * edits survive (review #5); without it, a 2-way merge. Returns the fresh
+   * page's `updatedAt` for the loop-guard.
    */
   private async importPageMarkdown(
     ctx: GitSyncBindContext,
     pageId: string,
     fullMarkdown: string,
+    baseMarkdown?: string | null,
   ): Promise<{ updatedAt?: string }> {
     const { body } = parseDocmostMarkdown(fullMarkdown);
     const doc = await markdownToProseMirror(body);
-    await this.writeBody(pageId, doc, ctx.userId);
+
+    let baseDoc: unknown;
+    if (baseMarkdown != null) {
+      const { body: baseBody } = parseDocmostMarkdown(baseMarkdown);
+      baseDoc = await markdownToProseMirror(baseBody);
+    }
+
+    await this.writeBody(pageId, doc, ctx.userId, baseDoc);
 
     const page = await this.pageRepo.findById(pageId);
     return {
@@ -378,18 +389,23 @@ export class GitmostDataSourceService {
     pageId: string,
     prosemirrorJson: unknown,
     userId: string,
+    baseProsemirrorJson?: unknown,
   ): Promise<void> {
     const documentName = `page.${pageId}`;
 
-    // Build the incoming Yjs doc BEFORE opening the connection / touching the
-    // live doc. If the transform throws (a malformed/unsupported doc) we must NOT
-    // have mutated the live body — otherwise a conversion failure could leave the
-    // page empty (review #5 — crash-safe conversion).
+    // Build the incoming (and base) Yjs docs BEFORE opening the connection /
+    // touching the live doc. If a transform throws (a malformed/unsupported doc)
+    // we must NOT have mutated the live body — otherwise a conversion failure
+    // could leave the page empty (review #5 — crash-safe conversion).
     const targetDoc = TiptapTransformer.toYdoc(
       prosemirrorJson,
       'default',
       tiptapExtensions,
     );
+    const baseDoc =
+      baseProsemirrorJson != null
+        ? TiptapTransformer.toYdoc(baseProsemirrorJson, 'default', tiptapExtensions)
+        : null;
 
     const conn = await this.collabGateway.openDirectConnection(documentName, {
       actor: 'git-sync',
@@ -400,15 +416,24 @@ export class GitmostDataSourceService {
     });
     try {
       await conn.transact((doc) => {
+        const liveFrag = doc.getXmlFragment('default');
+        const targetFrag = targetDoc.getXmlFragment('default');
         // Block-level MERGE rather than a full-body replace (review #5): diff the
         // live body against the incoming git body and apply only the blocks that
-        // actually changed. Blocks a human is concurrently editing — anything git
-        // did not change — are left untouched, and an unchanged resync is a 0-op
-        // write. Yjs CRDT-merges the minimal ops with live edits.
-        mergeXmlFragments(
-          doc.getXmlFragment('default'),
-          targetDoc.getXmlFragment('default'),
-        );
+        // actually changed; concurrently-edited blocks are left untouched and an
+        // unchanged resync is a 0-op write. With a `base` (the last-synced
+        // version) do a THREE-WAY merge so a block ONLY the human changed is kept
+        // and a block ONLY git changed is taken (conflicts -> git). Without a base
+        // (e.g. createPage), fall back to the 2-way merge.
+        if (baseDoc) {
+          mergeXmlFragments3Way(
+            liveFrag,
+            targetFrag,
+            baseDoc.getXmlFragment('default'),
+          );
+        } else {
+          mergeXmlFragments(liveFrag, targetFrag);
+        }
       });
     } finally {
       await conn.disconnect();

apps/server/src/integrations/git-sync/services/three-way-merge.spec.ts

@@ -0,0 +1,112 @@
+import { diff3Plan, type Pick } from './three-way-merge';
+
+// Materialize a plan into the merged key sequence for assertion.
+function apply(plan: Pick[], live: string[], target: string[]): string[] {
+  return plan.map((p) => (p.src === 'live' ? live[p.index] : target[p.index]));
+}
+
+const merge = (o: string[], a: string[], b: string[]): string[] =>
+  apply(diff3Plan(o, a, b), a, b);
+
+describe('diff3Plan (block-level three-way merge)', () => {
+  it('identical on all three sides -> unchanged (all from live)', () => {
+    const plan = diff3Plan(['1', '2', '3'], ['1', '2', '3'], ['1', '2', '3']);
+    expect(plan.every((p) => p.src === 'live')).toBe(true);
+    expect(apply(plan, ['1', '2', '3'], ['1', '2', '3'])).toEqual(['1', '2', '3']);
+  });
+
+  it('git changed a block the human did not -> takes git', () => {
+    expect(merge(['1', '2', '3'], ['1', '2', '3'], ['1', '9', '3'])).toEqual([
+      '1',
+      '9',
+      '3',
+    ]);
+  });
+
+  it('human changed a block git did not -> KEEPS the human edit (the core 3-way win)', () => {
+    expect(merge(['1', '2', '3'], ['1', 'H', '3'], ['1', '2', '3'])).toEqual([
+      '1',
+      'H',
+      '3',
+    ]);
+  });
+
+  it('human and git changed DIFFERENT blocks -> both preserved', () => {
+    // human rewrote block 1, git rewrote block 3.
+    expect(merge(['1', '2', '3'], ['H', '2', '3'], ['1', '2', 'G'])).toEqual([
+      'H',
+      '2',
+      'G',
+    ]);
+  });
+
+  it('human inserted a block AND git changed a different block -> both preserved', () => {
+    expect(
+      merge(['1', '2', '3'], ['1', '1.5', '2', '3'], ['1', '2', 'G']),
+    ).toEqual(['1', '1.5', '2', 'G']);
+  });
+
+  it('both changed the SAME block -> conflict resolves to git', () => {
+    expect(merge(['1', '2', '3'], ['1', 'H', '3'], ['1', 'G', '3'])).toEqual([
+      '1',
+      'G',
+      '3',
+    ]);
+  });
+
+  it('both made the SAME edit -> that edit (no duplication)', () => {
+    expect(merge(['1', '2', '3'], ['1', 'X', '3'], ['1', 'X', '3'])).toEqual([
+      '1',
+      'X',
+      '3',
+    ]);
+  });
+
+  it('human deleted a block git left alone -> deletion preserved', () => {
+    expect(merge(['1', '2', '3'], ['1', '3'], ['1', '2', '3'])).toEqual([
+      '1',
+      '3',
+    ]);
+  });
+
+  it('git deleted a block the human left alone -> deletion applied', () => {
+    expect(merge(['1', '2', '3'], ['1', '2', '3'], ['1', '3'])).toEqual([
+      '1',
+      '3',
+    ]);
+  });
+
+  it('both deleted the same block -> gone (no conflict)', () => {
+    expect(merge(['1', '2', '3'], ['1', '3'], ['1', '3'])).toEqual(['1', '3']);
+  });
+
+  it('git appended a trailing block -> appended', () => {
+    expect(merge(['1', '2'], ['1', '2'], ['1', '2', '3'])).toEqual([
+      '1',
+      '2',
+      '3',
+    ]);
+  });
+
+  it('human appended a trailing block git did not -> kept', () => {
+    expect(merge(['1', '2'], ['1', '2', '3'], ['1', '2'])).toEqual([
+      '1',
+      '2',
+      '3',
+    ]);
+  });
+
+  it('empty base, git provides content (brand-new page body) -> git content', () => {
+    expect(merge([], [], ['1', '2'])).toEqual(['1', '2']);
+  });
+
+  it('git changed block 1, human edited block 3, far apart -> both kept', () => {
+    expect(
+      merge(
+        ['a', 'b', 'c', 'd', 'e'],
+        ['a', 'b', 'c', 'd', 'E'],
+        ['A', 'b', 'c', 'd', 'e'],
+      ),
+    ).toEqual(['A', 'b', 'c', 'd', 'E']);
+  });
+});

apps/server/src/integrations/git-sync/services/three-way-merge.ts

@@ -0,0 +1,128 @@
+/**
+ * Pure block-level THREE-WAY merge planner (diff3) over arrays of opaque block
+ * keys. Used by the git-sync body write to merge an incoming git body into the
+ * live page using the last-synced version as the common ancestor (review #5):
+ *
+ *   - a block only the human changed (live != base, git == base) -> keep LIVE
+ *   - a block only git changed       (git != base, live == base) -> take GIT
+ *   - a block both sides changed (a real conflict)               -> GIT wins
+ *   - inserts/deletes from either side are preserved when unambiguous
+ *
+ * Content-agnostic: it works on string keys and returns the merged block order as
+ * picks ({ src: 'live'|'target', index }) — the caller (the Yjs applier)
+ * materializes them — so the whole algorithm is unit-testable on plain arrays.
+ *
+ * Algorithm: anchor on base blocks present (unchanged) in BOTH live and target
+ * (their LCS-with-base intersection). Between consecutive anchors lies one region
+ * the human and/or git rewrote; resolve each region three-way. Stable anchor
+ * blocks are emitted from LIVE so the applier keeps the existing Yjs block
+ * instances (and the human's in-flight edits) in place.
+ */
+
+/** Matched index pairs of the longest common subsequence of `a` and `b`. */
+function lcsPairs(a: string[], b: string[]): Array<[number, number]> {
+  const n = a.length;
+  const m = b.length;
+  const dp: number[][] = Array.from({ length: n + 1 }, () =>
+    new Array(m + 1).fill(0),
+  );
+  for (let i = n - 1; i >= 0; i--) {
+    for (let j = m - 1; j >= 0; j--) {
+      dp[i][j] =
+        a[i] === b[j]
+          ? dp[i + 1][j + 1] + 1
+          : Math.max(dp[i + 1][j], dp[i][j + 1]);
+    }
+  }
+  const pairs: Array<[number, number]> = [];
+  let i = 0;
+  let j = 0;
+  while (i < n && j < m) {
+    if (a[i] === b[j]) {
+      pairs.push([i, j]);
+      i++;
+      j++;
+    } else if (dp[i + 1][j] >= dp[i][j + 1]) {
+      i++;
+    } else {
+      j++;
+    }
+  }
+  return pairs;
+}
+
+/** o-index -> matched index in the other side (only for LCS-matched blocks). */
+function matchMap(pairs: Array<[number, number]>): Map<number, number> {
+  const m = new Map<number, number>();
+  for (const [o, x] of pairs) m.set(o, x);
+  return m;
+}
+
+const keysEqual = (x: string[], y: string[]): boolean =>
+  x.length === y.length && x.every((v, k) => v === y[k]);
+
+/**
+ * Resolve one region (the live slice, target slice, and base slice that occupy
+ * the same span between two anchors). 'target' (git) wins ties and conflicts.
+ */
+function decideRegion(
+  aRegion: string[],
+  bRegion: string[],
+  oRegion: string[],
+): 'live' | 'target' {
+  if (keysEqual(aRegion, bRegion)) return 'target'; // same edit on both sides
+  if (keysEqual(aRegion, oRegion)) return 'target'; // live unchanged -> git's edit
+  if (keysEqual(bRegion, oRegion)) return 'live'; // git unchanged -> human's edit
+  return 'target'; // genuine conflict -> git wins
+}
+
+export interface Pick {
+  src: 'live' | 'target';
+  index: number;
+}
+
+/**
+ * Three-way merge of base `o`, live `a`, target `b` (arrays of block keys).
+ * Returns the merged block order as picks from live/target.
+ */
+export function diff3Plan(o: string[], a: string[], b: string[]): Pick[] {
+  const oToA = matchMap(lcsPairs(o, a));
+  const oToB = matchMap(lcsPairs(o, b));
+
+  const res: Pick[] = [];
+  let oi = 0;
+  let ai = 0;
+  let bi = 0;
+
+  for (;;) {
+    // Next anchor: a base block present (unchanged) in BOTH live and target.
+    let anchor = oi;
+    while (anchor < o.length && !(oToA.has(anchor) && oToB.has(anchor))) {
+      anchor++;
+    }
+    const aEnd = anchor < o.length ? (oToA.get(anchor) as number) : a.length;
+    const bEnd = anchor < o.length ? (oToB.get(anchor) as number) : b.length;
+
+    // Resolve the region [oi,anchor) that one or both sides rewrote/inserted.
+    const take = decideRegion(
+      a.slice(ai, aEnd),
+      b.slice(bi, bEnd),
+      o.slice(oi, anchor),
+    );
+    if (take === 'live') {
+      for (let k = ai; k < aEnd; k++) res.push({ src: 'live', index: k });
+    } else {
+      for (let k = bi; k < bEnd; k++) res.push({ src: 'target', index: k });
+    }
+
+    if (anchor >= o.length) break;
+
+    // Emit the stable anchor block from LIVE, then advance past it on all sides.
+    res.push({ src: 'live', index: aEnd });
+    ai = aEnd + 1;
+    bi = bEnd + 1;
+    oi = anchor + 1;
+  }
+
+  return res;
+}

apps/server/src/integrations/git-sync/services/yjs-body-merge.spec.ts

@@ -2,6 +2,7 @@ import * as Y from 'yjs';
 
 import {
   mergeXmlFragments,
+  mergeXmlFragments3Way,
   cloneXmlNode,
   diffBlocks,
 } from './yjs-body-merge';
@@ -142,6 +143,57 @@ describe('yjs-body-merge', () => {
     });
   });
 
+  describe('mergeXmlFragments3Way', () => {
+    it('keeps a human edit to one block while applying a git change to another (3-way)', () => {
+      // base (last synced): [a, b, c]. Human edited block 0 in the live doc; git
+      // changed block 2 in the incoming file. 3-way must keep BOTH — the 2-way
+      // merge would instead revert the human's block 0 to git's stale version.
+      const base = new Y.Doc();
+      const live = new Y.Doc();
+      const target = new Y.Doc();
+      const baseFrag = buildFragment(base, ['a', 'b', 'c']);
+      const liveFrag = buildFragment(live, ['HUMAN', 'b', 'c']);
+      const targetFrag = buildFragment(target, ['a', 'b', 'GIT']);
+
+      const humanBlock = liveFrag.get(0); // the human's live instance
+      live.transact(() =>
+        mergeXmlFragments3Way(liveFrag, targetFrag, baseFrag),
+      );
+
+      // Human's block preserved as the SAME instance; git's change applied.
+      expect(liveFrag.get(0)).toBe(humanBlock);
+      expect(texts(liveFrag)).toEqual(['HUMAN', 'b', 'GIT']);
+    });
+
+    it('a block both sides changed resolves to git (conflict policy)', () => {
+      const base = new Y.Doc();
+      const live = new Y.Doc();
+      const target = new Y.Doc();
+      const baseFrag = buildFragment(base, ['a', 'b', 'c']);
+      const liveFrag = buildFragment(live, ['a', 'HUMAN', 'c']);
+      const targetFrag = buildFragment(target, ['a', 'GIT', 'c']);
+
+      live.transact(() =>
+        mergeXmlFragments3Way(liveFrag, targetFrag, baseFrag),
+      );
+      expect(texts(liveFrag)).toEqual(['a', 'GIT', 'c']);
+    });
+
+    it('git change with no concurrent human edit (live == base) applies cleanly', () => {
+      const base = new Y.Doc();
+      const live = new Y.Doc();
+      const target = new Y.Doc();
+      const baseFrag = buildFragment(base, ['a', 'b']);
+      const liveFrag = buildFragment(live, ['a', 'b']);
+      const targetFrag = buildFragment(target, ['a', 'B2']);
+
+      live.transact(() =>
+        mergeXmlFragments3Way(liveFrag, targetFrag, baseFrag),
+      );
+      expect(texts(liveFrag)).toEqual(['a', 'B2']);
+    });
+  });
+
   describe('cloneXmlNode', () => {
     it('preserves text marks (XmlText delta) across docs', () => {
       const src = new Y.Doc();

apps/server/src/integrations/git-sync/services/yjs-body-merge.ts

@@ -1,5 +1,7 @@
 import * as Y from 'yjs';
 
+import { diff3Plan } from './three-way-merge';
+
 /**
  * Block-level merge of an incoming (git) page body into a LIVE Yjs document,
  * replacing the previous full-body "delete everything + re-insert" write that
@@ -158,3 +160,42 @@ export function mergeXmlFragments(
   }
   return applied;
 }
+
+/**
+ * THREE-WAY block merge: reconcile `live` toward `target` using `base` (the
+ * last-synced common ancestor) so a block only the human changed is KEPT and a
+ * block only git changed is taken — instead of git's version always winning
+ * (review #5). Conflicts (both changed the same block) resolve to git.
+ *
+ * Implementation: diff3Plan computes the merged block ORDER (picks from live or
+ * target); we materialize that as a virtual target fragment and reuse the 2-way
+ * `mergeXmlFragments` to splice it into `live` minimally (so untouched live block
+ * instances — and their in-flight edits — stay put). MUST be called inside a Yjs
+ * transaction. Returns the number of block operations applied.
+ */
+export function mergeXmlFragments3Way(
+  live: Y.XmlFragment,
+  target: Y.XmlFragment,
+  base: Y.XmlFragment,
+): number {
+  const liveKids = live.toArray();
+  const targetKids = target.toArray();
+  const liveKeys = liveKids.map(key);
+  const targetKeys = targetKids.map(key);
+  const baseKeys = base.toArray().map(key);
+
+  const plan = diff3Plan(baseKeys, liveKeys, targetKeys);
+
+  // Build the merged block sequence in a throwaway doc, cloning from whichever
+  // side each pick came from, then 2-way merge it back into the live fragment.
+  const merged = new Y.Doc();
+  const mergedFrag = merged.getXmlFragment('default');
+  const nodes = plan.map((p) =>
+    cloneXmlNode(
+      (p.src === 'live' ? liveKids[p.index] : targetKids[p.index]) as XmlNode,
+    ),
+  );
+  if (nodes.length) mergedFrag.insert(0, nodes);
+
+  return mergeXmlFragments(live, mergedFrag);
+}

packages/git-sync/src/engine/client.types.ts

@@ -73,14 +73,19 @@ export interface GitSyncClient {
   // --- writes (push) --------------------------------------------------------
 
   /**
-   * Replace a page's body from a self-contained markdown file (meta + body).
-   * The collab/Yjs write path (SPEC §2/§15.6) — never a raw jsonb overwrite.
+   * Merge a page's body from a self-contained markdown file (meta + body). The
+   * collab/Yjs write path (SPEC §2/§15.6) — never a raw jsonb overwrite.
    * `applyPushActions` reads only an optional `updatedAt` off the result
    * (via `extractUpdatedAt`, tolerant of extra fields).
+   *
+   * `baseMarkdown` is the last-synced version of the file (`refs/docmost/
+   * last-pushed`), the common ancestor for a THREE-WAY merge against the live
+   * doc so concurrent human edits survive (review #5). Optional/null -> 2-way.
    */
   importPageMarkdown(
     pageId: string,
     fullMarkdown: string,
+    baseMarkdown?: string | null,
   ): Promise<{ updatedAt?: string; [key: string]: unknown }>;
 
   /**

packages/git-sync/src/engine/push.ts

@@ -552,7 +552,18 @@ export async function applyPushActions(
   for (const u of actions.updates) {
     try {
       const fullMarkdown = await deps.readFile(u.path);
-      const result = await client.importPageMarkdown(u.pageId, fullMarkdown);
+      // The last-synced version of this file (pre-image) is the common ancestor
+      // for a 3-way merge against the live page, so concurrent human edits are
+      // not clobbered (review #5). Null when the file is new at last-pushed.
+      const baseMarkdown = await deps.git.showFileAtRef(
+        LAST_PUSHED_REF,
+        u.path,
+      );
+      const result = await client.importPageMarkdown(
+        u.pageId,
+        fullMarkdown,
+        baseMarkdown,
+      );
       updated++;
       // §10 loop-guard data: hash the body we pushed + capture `updatedAt`.
       pushed.push({

packages/git-sync/test/apply-push-actions.test.ts

@@ -143,12 +143,36 @@ describe('applyPushActions — update (collab path, SPEC §2/§15.6)', () => {
     expect(res.updated).toBe(1);
     // The collab/Yjs write path is used — NOT a raw jsonb overwrite.
     expect(client.importPageMarkdown).toHaveBeenCalledTimes(1);
-    expect(client.importPageMarkdown).toHaveBeenCalledWith('p-1', fileBody);
+    expect(client.importPageMarkdown).toHaveBeenCalledWith('p-1', fileBody, null);
     // No raw-overwrite path exists on the injected client surface at all.
     expect((client as any).updatePageJson).toBeUndefined();
     expect(client.createPage).not.toHaveBeenCalled();
     expect(client.deletePage).not.toHaveBeenCalled();
   });
+
+  it('forwards the last-pushed base body (3-way merge ancestor) when present', async () => {
+    const baseBody =
+      '<!-- docmost:meta\n{"version":1,"pageId":"p-1"}\n-->\n\nbase body\n';
+    const fileBody =
+      '<!-- docmost:meta\n{"version":1,"pageId":"p-1"}\n-->\n\nupdated body\n';
+    const client = makeClient();
+    // The pre-image (refs/docmost/last-pushed) carries the base version.
+    const { git } = makeGit({ prevTree: { 'Doc.md': baseBody } });
+    const fs = makeFs({ 'Doc.md': fileBody });
+
+    await applyPushActions(
+      deps(client, git, fs),
+      actions({ updates: [{ pageId: 'p-1', path: 'Doc.md' }] }),
+    );
+
+    // importPageMarkdown receives the base so the server can 3-way merge it.
+    expect(client.importPageMarkdown).toHaveBeenCalledWith(
+      'p-1',
+      fileBody,
+      baseBody,
+    );
+    expect(git.showFileAtRef).toHaveBeenCalledWith(LAST_PUSHED_REF, 'Doc.md');
+  });
 });
 
 describe('applyPushActions — create (assigned pageId written back to meta)', () => {
@@ -542,8 +566,8 @@ describe('applyPushActions — per-page error isolation + refs gated on success
     // The 1st and 3rd were applied; the 2nd threw.
     expect(res.updated).toBe(2);
     expect(client.importPageMarkdown).toHaveBeenCalledTimes(3);
-    expect(client.importPageMarkdown).toHaveBeenNthCalledWith(1, 'p-a', 'a body');
-    expect(client.importPageMarkdown).toHaveBeenNthCalledWith(3, 'p-c', 'c body');
+    expect(client.importPageMarkdown).toHaveBeenNthCalledWith(1, 'p-a', 'a body', null);
+    expect(client.importPageMarkdown).toHaveBeenNthCalledWith(3, 'p-c', 'c body', null);
 
     // The failure is recorded with kind/pageId/path/error.
     expect(res.failures).toEqual([
@@ -649,7 +673,7 @@ describe('applyPushActions — mixed batch + skipped passthrough', () => {
     expect(res.writtenBack).toEqual([{ path: 'N.md', pageId: 'created-1' }]);
     expect(res.skipped).toEqual(skipped);
     expect(updateRefCalls).toEqual([{ ref: LAST_PUSHED_REF, target: 'sha-9' }]);
-    expect(client.importPageMarkdown).toHaveBeenCalledWith('u-1', updFile);
+    expect(client.importPageMarkdown).toHaveBeenCalledWith('u-1', updFile, null);
     expect(client.deletePage).toHaveBeenCalledWith('d-1');
   });
 });

packages/git-sync/test/engine-gaps.test.ts

@@ -300,7 +300,11 @@ describe('applyPushActions (push.ts) — move prefetch isolation', () => {
     // The update and the delete in the SAME batch still applied.
     expect(res.updated).toBe(1);
     expect(res.deleted).toBe(1);
-    expect(client.importPageMarkdown).toHaveBeenCalledWith('u1', store['Up.md']);
+    expect(client.importPageMarkdown).toHaveBeenCalledWith(
+      'u1',
+      store['Up.md'],
+      null,
+    );
     expect(client.deletePage).toHaveBeenCalledWith('d1');
 
     // The broken move was ISOLATED: no movePage/renamePage call, recorded as a

packages/git-sync/test/run-push.test.ts

@@ -312,7 +312,7 @@ describe('runPush — --apply is the ONLY write path', () => {
 
     const res = await runPush(deps, { dryRun: false });
 
-    expect(client.importPageMarkdown).toHaveBeenCalledWith('p-9', file);
+    expect(client.importPageMarkdown).toHaveBeenCalledWith('p-9', file, null);
     expect(res.applied?.updated).toBe(1);
   });
 });