fix(typescript-fetch): remove barrel imports

[celluj34]

All text copied from #12236

Removing barrel exports significantly improves performance in situation where tree shaking is not possible. EG testing via jest. See #12081

Barrel exports are files that import and export a group of files. EG models/index.ts

This does not remove the index files. It just removes the internal dependency on them.

To verify, just make sure all the new imports point to a file that:

1. Exists
2. Contains the item being imported

Fixes #12081
Main credit goes to @orrin-naylor-instacart for the initial PR, I have just rebased against latest master

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---

Summary by cubic

Remove barrel imports from the TypeScript Fetch generator and switch to per-file model imports to improve performance where tree shaking isn’t available (e.g., Jest). Index files remain but are no longer used internally. Fixes #12081.

• Refactors
  • Replace models/index imports with per-file imports in ApiEntitiesRecord, apis, sagas, allSagas, and sagaApiManager; add explicit file extensions and correct model vs record paths.
  • Point runtime and saga imports to specific files instead of barrels.
  • No behavior changes to generated APIs or types.

^{Written for commit a991213. Summary will update on new commits.}

[cubic-dev-ai]

6 issues found across 5 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/resources/typescript-fetch/allSagas.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-fetch/allSagas.mustache:7">
P2: Per-API saga import omits `{{importFileExtension}}`, breaking ESM extension handling used elsewhere in the generator.</violation>

<violation number="2" location="modules/openapi-generator/src/main/resources/typescript-fetch/allSagas.mustache:7">
P1: Hard-coded saga import path "./classFilename" produces invalid imports; should reference the per-API saga file</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/typescript-fetch/sagas.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-fetch/sagas.mustache:17">
P2: Per-model model import omits `{{importFileExtension}}`, producing extensionless paths that can break ESM/NodeNext consumers.</violation>

<violation number="2" location="modules/openapi-generator/src/main/resources/typescript-fetch/sagas.mustache:17">
P1: Saga template now imports model files by class name, ignoring configured/sanitized filenames, breaking imports for non-default model file naming</violation>

<violation number="3" location="modules/openapi-generator/src/main/resources/typescript-fetch/sagas.mustache:23">
P2: Passthrough model import drops `{{importFileExtension}}`, leading to extensionless imports that can fail under ESM/NodeNext.</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache:10">
P2: Per-model imports omit configurable `{{importFileExtension}}`, breaking ESM builds requiring explicit extensions (.js)</violation>
</file>

---

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_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

3 issues found across 5 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/resources/typescript-fetch/sagaApiManager.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-fetch/sagaApiManager.mustache:4">
P2: Missing `{{importFileExtension}}` in runtime import breaks ESM extension resolution</violation>

<violation number="2" location="modules/openapi-generator/src/main/resources/typescript-fetch/sagaApiManager.mustache:10">
P2: Missing `{{importFileExtension}}` in per-API imports causes ESM resolution failures</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/typescript-fetch/ApiEntitiesRecord.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/typescript-fetch/ApiEntitiesRecord.mustache:8">
P2: Generated import uses `{{classname}}` instead of `{{classFilename}}`, breaking paths when filenames differ</violation>
</file>

---

Since this is your first cubic review, here's how it works:

• cubic automatically reviews your code and comments on bugs and improvements
• Teach cubic by replying to its comments. cubic learns from your replies and gets better over time
• Ask questions if you need clarification on any suggestion

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[celluj34]

/cc Typescript committee members (@TiFu @taxpon @sebastianhaas @kenisteward @Vrolijkx @macjohnny @topce @akehir @petejohansonxo @amakhrov @davidgamero @mkusaka @joscha)