Slate Browser Next API Candidates Matrix

Specialist testing/proof doc. For current queue and roadmap truth, see master-roadmap.md.

Proposed API research only. This file does not define the current shipped slate-browser surface.

Purpose

This is the deeper follow-up to next-api-candidates.md.

It answers:

• which candidate APIs are actually worth shipping
• which current Slate test pain each API would remove
• which repo proved the idea
• which ideas should stay out

Current Test Pain

Across Slate’s current Playwright example suite in /Users/zbeyens/git/slate-v2/playwright/integration/examples:

• raw page.goto(...): 23
• raw getByRole('textbox'): 41
• raw selectText(): 7
• raw DOM selection surgery: document.createRange / window.getSelection() / addRange(...): 5
• raw boundingBox() assertions: 2

This matters because the best next APIs should erase repeated high-noise setup, not just add another cute helper name.

Evaluation Rules

Ship an API only if it:

1. removes real repeated pain from the current suite
2. makes tests more Slate-shaped
3. stays honest about browser truth
4. does not smuggle in a fake backend abstraction

Deep Matrix

1. ready Contract

Status:

• ship now

Candidate:

const editor = await openExample(page, "custom-placeholder", {
  ready: {
    editor: "visible",
    text: /Hello/,
    placeholder: "visible",
    selection: "settled",
    selector: "#document-outline",
  },
});

Primary evidence:

• Lexical initialize(...): index.mjs

Current pain it removes:

• ad hoc page.goto(...)
• one-off waits for placeholder, text, or extra selectors
• hidden selection-settle timing

Why it is strong:

• highest-leverage setup seam
• directly supports the next zero-width / IME / empty-state gauntlet
• gives later cross-browser lanes a sane base

Risk:

• turning into a kitchen sink

Rule:

• keep it narrow and readiness-only

2. editor.selection.select(...)

Status:

• ship now

Candidate:

await editor.selection.select({
  anchor: { path: [0, 0], offset: 0 },
  focus: { path: [0, 0], offset: 5 },
});

Companions:

await editor.selection.collapse({ path: [0, 0], offset: 0 });
await editor.selection.selectBlock([1]);

Primary evidence:

• current suite still uses raw DOM range surgery in inlines.test.ts
• edix snapshot-based selection setup/inspection: edix.ts

Current pain it removes:

• direct DOM range manipulation
• fragile node-text-anchor assumptions

Why it is strong:

• today the harness can assert semantic selection but cannot create one
• that is backwards

Risk:

• path mapping bugs if implemented sloppily

Rule:

• semantic selection setup first
• gesture APIs later

3. editor.get.blockTexts() / editor.assert.blockTexts(...)

Status:

• ship now

Candidate:

expect(await editor.get.blockTexts()).toEqual(["alpha", "beta"]);
await editor.assert.blockTexts(["alpha", "beta"]);

Companions:

expect(await editor.get.selectedText()).toBe("alpha");
expect(await editor.get.textAt([1])).toBe("beta");

Primary evidence:

• edix getText(...) and getSeletedText(...): edix.ts

Current pain it removes:

• overreliance on raw HTML assertions
• lossy flat get.text()

Why it is strong:

• block text is much closer to Slate semantics than DOM strings
• also easy to read in failures

Risk:

• overreaching into full Slate JSON reconstruction

Rule:

• stop at block-text semantics
• do not add fake document deserialization here

4. editor.snapshot()

Status:

• ship now

Candidate:

const snapshot = await editor.snapshot();

Likely payload:

• text
• blockTexts
• selectedText
• selection
• domSelection
• placeholderShape

Primary evidence:

• use-editable getState(): useEditable.ts

Current pain it removes:

• multi-call debugging boilerplate
• weak failure artifacts

Why it is strong:

• one-call truth dump is the best debugging upgrade per line of API

Risk:

• bloated snapshot shape

Rule:

• aggregate existing truths only
• do not hide extra behavior in snapshot generation

5. Tolerant Selection Assertions

Status:

• ship after tranche 1

Candidate:

await editor.assert.selection({
  anchor: { path: [0, 0], offset: [0, 1] },
  focus: { path: [0, 0], offset: [0, 1] },
});

Primary evidence:

• Lexical tolerated offset assertions: index.mjs

Current pain it removes:

• future cross-browser selection variance
• some zero-width / line-break normalization fuzz

Why it is not tranche 1:

• exact selection APIs matter more than tolerant ones right now

Rule:

• tolerant expectations must be explicit

6. HTML Normalization Options

Status:

• ship after tranche 1

Candidate:

await editor.assert.htmlEquals(expected, {
  ignoreClasses: true,
  ignoreInlineStyles: true,
  ignoreDir: true,
});

Primary evidence:

• Lexical assertHTML(...) options: index.mjs

Current pain it removes:

• brittle browser-sensitive HTML exactness

Why it is not tranche 1:

• better semantic getters beat better HTML massaging

7. editor.get.selectedText()

Status:

• strong maybe

Candidate:

expect(await editor.get.selectedText()).toBe("wise quote");

Primary evidence:

• edix getSeletedText(...): edix.ts

Current pain it removes:

• awkward text-selection assertions via HTML or DOM

Why it matters:

• especially useful for copy/selection seams

Why it is not higher:

• blockTexts and full snapshot() cover more surface first

8. Real Clipboard Read Helpers

Status:

• strong maybe

Candidate:

expect(await editor.clipboard.readText()).toContain("Hello");
expect(await editor.clipboard.readHtml()).toContain("<p");

Primary evidence:

• edix readClipboard(...): utils.ts

Current pain it removes:

• inability to prove the real post-copy clipboard state directly

Why it matters:

• this is the most honest copy-path proof after real paste helpers

Why it is not higher:

• permission and stability questions are still worse than the top tranche

9. Alternate-Surface Scoping

Status:

• later

Problem:

• the current harness assumes one simple editable root via getByRole('textbox')
• Slate’s suite already has iframe and shadow DOM examples

Candidate directions:

const editor = await openExample(page, "iframe", {
  surface: "iframe",
});

or:

const editor = await openExample(page, 'shadow-dom', {
  resolveRoot: page => ...,
})

Current evidence:

• iframe.test.ts
• shadow-dom.test.ts

Why it matters:

• absolute-best framework eventually needs to handle non-trivial surfaces

Why it is later:

• this can leak Playwright-specific locator details fast
• the core editor semantics need to harden first

10. Path-Oriented Locators

Status:

• later

Candidate:

await editor.path([1]).click({ clickCount: 3 });
await editor.textNode([0, 0]).click();

Current pain it removes:

• raw locators plus .nth(...)
• block-selection setup by DOM position instead of Slate position

Primary evidence:

• current suite patterns in: select.test.ts

Why it matters:

• this is the most Slate-specific locator idea available

Why it is later:

• path mapping correctness comes first
• selection.select(...) buys more value first

11. Placeholder Content Assertions

Status:

• low priority

Candidate:

await editor.assert.placeholderText("Type something");

Current evidence:

• placeholder tests in placeholder.test.ts
• Tiptap’s focused placeholder option tests: placeholder.spec.ts

Why it matters:

• nicer than raw locators for placeholder tests

Why it is low priority:

• current frequency is low
• ready, selection.select, and blockTexts buy much more

Rejected

openFixture(...)

Reject.

Why:

• no real fixture lane exists
• example-mounted truth is still the right seam

editor.driver()

Reject.

Why:

• generic-driver escape hatch destroys the point of a Slate-shaped API

Synthetic Public Paste Helpers

Reject.

Why:

• real browser clipboard write plus real paste gesture already exists

One Mega Driver Abstraction

Reject.

Why:

• current backend is Playwright-first
• pretending otherwise now is abstraction cosplay

Recommended Phasing

Phase 1

Ship:

1. ready contract
2. editor.selection.select(...)
3. editor.get.blockTexts() / assert.blockTexts(...)
4. editor.snapshot()

Phase 2

Ship:

1. tolerant selection assertions
2. HTML normalization options
3. maybe editor.get.selectedText()

Phase 3

Evaluate:

1. real clipboard read helpers
2. alternate-surface scoping
3. path-oriented locators

Bottom Line

After the deeper pass, the next tranche is still the same.

That is a good sign.

The absolute-best next APIs are:

• readiness
• semantic selection setup
• semantic block-text state
• one-call snapshots

Everything else is either follow-on work or bait.