Suggest mode 1/9: editor intent (edit/suggest/view) and experiment gate

[adamsilverstein]

Part of #73411

What's in this PR

Adds the session-scoped editor intent state (private setEditorIntent
action / getEditorIntent selector), the Edit / Suggest / View switcher in
the editor options menu, Google Docs convention keyboard shortcuts, and a
read-only view intent via isPreviewMode. The Suggestion Mode experiment
flag and the gate helpers (isSuggestionModeEnabled / useCanSuggest) land
here so every later layer gates on the same predicate. No suggestion
capture or storage yet.

The view intent's read-only contract is enforced here too, in the layer
that promises it: preview mode is added to the memoized insertion
selectors' dependants so flipping it at runtime invalidates their cached
answers, the writing flow's cross-block input handling bails out while
the canvas is a preview, and the Block Inserter toggle is disabled (an
open inserter is closed on the way in). This was originally #81661 on top
of the stack and moved down here so it can be reviewed next to the intent
it belongs to.

Screenshot

The Edit / Suggest / View switcher in the editor Options menu, with the Google Docs style shortcuts alongside each mode:

Mode group in the editor Options menu showing Editing, Suggesting and Viewing

Testing

This is one layer of the stack. To exercise the whole feature, #78994 bundles every layer into one branch and builds it in Playground:

👉 https://playground.wordpress.net/gutenberg.html?pr=78994

Enable Gutenberg > Experiments > Collaboration > Suggestion Mode, then follow the walkthrough in #73411, which also explains how to review the stack layer by layer.

---

Suggest mode stack

This rebuilds the manually-stacked Suggest mode work (#73411) as a GitHub Stack of 9 small, independently reviewable PRs, each building on the one below it:

1. #80427 - editor intent (edit/suggest/view) + experiment gate
2. #80428 - suggestion storage, REST controller, provider
3. #80429 - block-level capture (attribute + structural)
4. #80430 - inline marker primitive
5. #80431 - inline suggestion operations
6. #80432 - review UI (Apply/Reject sidebar + summary)
7. #80433 - inline live wiring
8. #82047 - architecture documentation
9. #82048 - end-to-end test suite

Each follow up fix now sits in the layer that owns the code it changes, rather than piling onto the top of the stack. The whole feature can be exercised end-to-end via the combined testing branch #78994 (Playground). Behind the "Suggestion Mode" experiment (Gutenberg > Experiments).

---

AI Use

Code and description both written with 🤖 Claude Code. I will review and test.

[github-actions]

Size Change: +1.92 kB (+0.02%)

Total Size: 7.91 MB

📦 View Changed

Filename	Size	Change
build/scripts/block-editor/index.min.js	478 kB	+31 B (+0.01%)
build/scripts/editor/index.min.js	582 kB	+1.89 kB (+0.33%)

_{compressed-size-action}

[github-actions]

Flaky tests detected in 5df3684.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/33116177758
📝 Reported tests:

refuses the drop and uploads nothing in /test/e2e/specs/editor/various/single-file-placeholder-drop.spec.js, passed after 1 failed attempt.

Error: expect(received).toHaveLength(expected)

Expected length: 0
Received length: 2
Received array:  [{"_links": {"about": [{"href": "http://localhost:8889/wp-json/wp/v2/types/attachment"}], "author": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/users/1"}], "collection": [{"href": "http://localhost:8889/wp-json/wp/v2/media"}], "curies": [{"href": "https://api.w.org/{rel}", "name": "wp", "templated": true}], "replies": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/comments?post=106"}], "self": [{"href": "http://localhost:8889/wp-json/wp/v2/media/106", "targetHints": {"allow": ["GET", "POST", "PUT", "PATCH", "DELETE"]}}], "wp:attached-to": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/posts/104", "id": 104, "post_type": "post"}]}, "alt_text": "", "author": 1, "caption": {"rendered": ""}, "class_list": ["post-106", "attachment", "type-attachment", "status-inherit", "hentry", "entry"], "comment_status": "open", "date": "2026-08-27T21:13:31", "date_gmt": "2026-08-27T21:13:31", "description": {"rendered": "<p class=\"attachment\"><a href='http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK-1.png'><img loading=\"lazy\" decoding=\"async\" width=\"10\" height=\"10\" src=\"http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK-1.png\" class=\"attachment-medium size-medium\" alt=\"\" style=\"width:100%;height:100%;max-width:10px;\" /></a></p>
"}, "featured_media": 0, "filename": "10x10_e2e_test_image_z9T8jK-1.png", "filesize": 80, "guid": {"rendered": "http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK-1.png"}, "id": 106, "link": "http://localhost:8889/?attachment_id=106", "media_details": {"file": "2026/08/10x10_e2e_test_image_z9T8jK-1.png", "filesize": 80, "height": 10, "image_meta": {"alt": "", "aperture": "0", "camera": "", "caption": "", "copyright": "", "created_timestamp": "0", "credit": "", "focal_length": "0", "iso": "0", "keywords": [], "orientation": "0", "shutter_speed": "0", "title": ""}, "sizes": {}, "width": 10}, "media_type": "image", "meta": [], "mime_type": "image/png", "modified": "2026-08-27T21:13:31", "modified_gmt": "2026-08-27T21:13:31", "ping_status": "closed", "post": 104, "slug": "10x10_e2e_test_image_z9t8jk-2", "source_url": "http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK-1.png", "status": "inherit", "template": "", "title": {"rendered": "10x10_e2e_test_image_z9T8jK"}, "type": "attachment"}, {"_links": {"about": [{"href": "http://localhost:8889/wp-json/wp/v2/types/attachment"}], "author": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/users/1"}], "collection": [{"href": "http://localhost:8889/wp-json/wp/v2/media"}], "curies": [{"href": "https://api.w.org/{rel}", "name": "wp", "templated": true}], "replies": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/comments?post=105"}], "self": [{"href": "http://localhost:8889/wp-json/wp/v2/media/105", "targetHints": {"allow": ["GET", "POST", "PUT", "PATCH", "DELETE"]}}], "wp:attached-to": [{"embeddable": true, "href": "http://localhost:8889/wp-json/wp/v2/posts/104", "id": 104, "post_type": "post"}]}, "alt_text": "", "author": 1, "caption": {"rendered": ""}, "class_list": ["post-105", "attachment", "type-attachment", "status-inherit", "hentry", "entry"], "comment_status": "open", "date": "2026-08-27T21:13:31", "date_gmt": "2026-08-27T21:13:31", "description": {"rendered": "<p class=\"attachment\"><a href='http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK.png'><img loading=\"lazy\" decoding=\"async\" width=\"10\" height=\"10\" src=\"http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK.png\" class=\"attachment-medium size-medium\" alt=\"\" style=\"width:100%;height:100%;max-width:10px;\" /></a></p>
"}, "featured_media": 0, "filename": "10x10_e2e_test_image_z9T8jK.png", "filesize": 80, "guid": {"rendered": "http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK.png"}, "id": 105, "link": "http://localhost:8889/?attachment_id=105", "media_details": {"file": "2026/08/10x10_e2e_test_image_z9T8jK.png", "filesize": 80, "height": 10, "image_meta": {"alt": "", "aperture": "0", "camera": "", "caption": "", "copyright": "", "created_timestamp": "0", "credit": "", "focal_length": "0", "iso": "0", "keywords": [], "orientation": "0", "shutter_speed": "0", "title": ""}, "sizes": {}, "width": 10}, "media_type": "image", "meta": [], "mime_type": "image/png", "modified": "2026-08-27T21:13:31", "modified_gmt": "2026-08-27T21:13:31", "ping_status": "closed", "post": 104, "slug": "10x10_e2e_test_image_z9t8jk", "source_url": "http://localhost:8889/wp-content/uploads/2026/08/10x10_e2e_test_image_z9T8jK.png", "status": "inherit", "template": "", "title": {"rendered": "10x10_e2e_test_image_z9T8jK"}, "type": "attachment"}]
    at /home/runner/work/gutenberg/gutenberg/test/e2e/specs/editor/various/single-file-placeholder-drop.spec.js:71:45

[aduth]

Hey 👋 I wanted to give you a heads-up since this pull request is affected by recent validation changes for changelog files.

#83043 adds additional validation for changelog files. You'll note that this pull request is currently failing a "Required changes from trunk" check.

What you'll need to do: You will need to either rebase or merge the latest code from trunk. In addition, a cursory review of open pull requests identified this pull request as potentially failing under the new validation checks. You will want to double-check that any changes to CHANGELOG.md files follow the Maintaining Changelogs guidance, which has been improved as part of these recent changes.

[adamsilverstein]

Claude took the latest review pass on this layer, here is the fix:

Viewing now also covers post settings. editPost() refuses any post-level field change (excerpt, author, slug, featured image and so on) while the intent is view, and shows a "can't be changed while viewing" snackbar. blocks, content and selection still pass, because the preview-mode canvas already guards those and block sync plus savePost rely on them. Two unit tests cover it: an excerpt edit in Viewing leaves the post clean, and content edits still go through. Fixed in eaaffa0.

[jasmussen]

Testing just this one in isolation, I get the same error noted here. Let me know if I'm doing something wrong.

[adamsilverstein]

Testing just this one in isolation, I get the same error noted here. Let me know if I'm doing something wrong.

this should be fixed now @jasmussen - thanks for letting me know it was broken!