refactor(editor): move the song-import flows to src/import.js (R2, step 29)

[byrongamatos]

What

Step 29 of the R2 module-extraction refactor: move the song-import flows out of the src/main.js monolith into a new native ES module src/import.js (no build step, source-served).

Covers:

• Add Keys arrangement import (GP / MIDI / MusicXML), including the RH/LH pair auto-select and the empty-keys path.
• Import Guitar/Bass from a GP file (add or replace an existing chart).
• The shared MIDI tempo-map offer dialog (_maybeOfferMidiTempoMap) and its @pure:midi-tempo-choice helpers.
• The shared unmapped-percussion mapper (_showDrumImportUnmappedModal).

How the seam is drawn

• The 11 window.editor* entry points become named exports; main.js re-attaches them to window (a module can't own window.foo =).
• _maybeOfferMidiTempoMap and _showDrumImportUnmappedModal are exported back — main.js's drum-import path still calls them.
• New host.effectiveAudioOffset hook lets import.js read the session offset (S.offset + the applied UI nudge) without importing back into main.js (would cycle). Defaults to 0.
• The @pure:guitar-import and @pure:midi-tempo-choice blocks move verbatim; the three suites that slice them (import_guitar_track, keys_pair_select, midi_tempo_import) are retargeted to src/import.js.

main.js drops ~1035 lines. No behavior change: every cross-boundary dependency (draw, updateArrangementSelector, updateStatus, resizeForLaneChange, effectiveAudioOffset) routes through host.

Verification

• 90/90 JS test suites pass; ESLint gate clean (0 errors).
• Codex preflight: 0 correctness issues.
• New headless harness (verify_import.py) drives a real Add-Keys import of a 71-byte synthetic SMF through the actual file input and editorDoAddKeys: asserts the 11 handlers bind, both modals open/close, the replace-target dropdown populates from S.arrangements, one arrangement is appended, the MIDI tempo-map modal appears, and the POSTed audio_offset reflects a seeded +5s offset — proving host.effectiveAudioOffset is wired. Negative-checked: neutering the hook flips that assertion to FAIL.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features
  • Added import workflows for Keys arrangements and guitar/bass tracks from GP, MIDI, and MusicXML files.
  • Added options to add or replace arrangements during guitar/bass imports.
  • Added MIDI tempo-map selection and unmapped percussion note-mapping prompts.
  • Added support for creating empty Keys arrangements.
• Bug Fixes
  • Improved import handling when host audio-offset configuration is unavailable.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

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Configuration used: defaults

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📥 Commits

Reviewing files that changed from the base of the PR and between f04cf49 and 3152db3.

📒 Files selected for processing (6)

• src/host.js
• src/import.js
• src/main.js
• tests/import_guitar_track.test.mjs
• tests/keys_pair_select.test.js
• tests/midi_tempo_import.test.mjs

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📝 Walkthrough

Walkthrough

Import workflows are extracted into src/import.js, covering Keys, guitar/bass, MIDI tempo maps, and unmapped percussion. main.js wires the exported handlers and audio-offset hook, while tests update their source extraction targets.

Changes

Song import workflows

Layer / File(s)	Summary
Import module wiring src/host.js, src/main.js	Adds the default effectiveAudioOffset host callback, wires import handlers, and removes moved import logic and unused imports from main.js.
Keys import flow src/import.js, tests/keys_pair_select.test.js, tests/import_guitar_track.test.mjs	Adds MusicXML, MIDI, GP, and empty-Keys imports with stale-request protection, track selection, arrangement registration, rendering, and updated helper extraction tests.
Guitar and bass import flow src/import.js, tests/import_guitar_track.test.mjs	Adds guitar/bass track filtering, family-constrained replacement targets, and add-or-replace arrangement import behavior.
Post-import triage src/import.js, tests/midi_tempo_import.test.mjs	Adds MIDI tempo-map choice and unmapped percussion mapping modals, including tempo application, hit deduplication, and updated tempo helper extraction tests.

Estimated code review effort: 4 (Complex) | ~60 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Editor
  participant import.js
  participant ImportAPI
  participant SessionState
  Editor->>import.js: Select Keys, GP, MIDI, or MusicXML file
  import.js->>ImportAPI: Parse or import file
  ImportAPI-->>import.js: Return tracks or arrangements
  import.js->>ImportAPI: Register imported arrangement
  ImportAPI-->>import.js: Return registered arrangement
  import.js->>SessionState: Append, render, and refresh editor state

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Possibly related PRs

• got-feedBack/feedBack-plugin-editor#127: Moves and wires the MIDI tempo-map offer flow into src/import.js.
• got-feedBack/feedBack-plugin-editor#168: Introduces related host-hook consolidation around the shared host object.
• got-feedBack/feedBack-plugin-editor#170: Shares the TempoGridCmd MIDI tempo-map flow and corresponding test updates.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch refactor/r2-step29-gp-import

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[Copilot]

Pull request overview

Refactors the editor’s song-import functionality by extracting Add-Keys (GP/MIDI/MusicXML), GP guitar/bass import (add/replace), and the shared post-import dialogs into a new native ES module (src/import.js), while keeping the existing window.editor* entrypoints by re-attaching them from src/main.js.

Changes:

• Added src/import.js and moved the import flows + shared MIDI tempo-map / unmapped-percussion dialogs into it as named exports.
• Updated src/main.js to import those handlers, re-attach them to window, and expose a new host.effectiveAudioOffset hook to avoid cyclic imports.
• Retargeted the “slice shipping code” unit tests to read from src/import.js instead of src/main.js.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/midi_tempo_import.test.mjs	Retargets tempo-map pure-helper extraction from src/main.js to src/import.js.
tests/keys_pair_select.test.js	Retargets _keysDefaultSelection extraction from src/main.js to src/import.js.
tests/import_guitar_track.test.mjs	Retargets guitar-import pure-helper extraction from src/main.js to src/import.js.
src/main.js	Imports src/import.js, wires host.effectiveAudioOffset, and re-attaches window.editor* import handlers.
src/import.js	New module containing the extracted import flows and shared dialogs, using host for cross-boundary calls.
src/host.js	Adds the effectiveAudioOffset host hook with a safe default.

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[byrongamatos]

Fixed — updated both comments (musicxml format, checkbox multi-select) in the follow-up commit.