feat: support ESM export for extend

[cexoso]

egg-ts-helper doesn't support code like this:

export const plus = (a: number, b: number) => a + b;

because egg-ts-helper generator d.ts file with content import xx from "./file" and xx mead defaultExport.
In this case, What we need is import * as xx from "./file".

this PR detect code, and generate import * as xx from "./file" when code just has export(not export defualt)

Summary by CodeRabbit

• New Features

  • Generator now detects whether target files use default or named exports and emits the appropriate import style (default import or import *) in generated output, improving compatibility and reducing manual adjustments.

• Tests

  • Updated expectations to check for explicit import statements instead of raw module paths.
  • Added coverage for both named and default export scenarios.
  • Revised fixtures to use named exports in helper examples, aligning with the new import behavior.

[Copilot]

Pull Request Overview

This PR adds support for ESM exports in the extend generator by detecting when a file contains only named exports (no default export) and generating appropriate import statements.

• Detects files with only named exports using a new hasExportWithoutDefault helper function
• Updates import statement generation to use namespace imports (import * as) when appropriate
• Modifies test fixture to use named exports instead of default export

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/generators/extend.ts	Adds export detection logic and updates import generation to handle named exports
test/fixtures/app/app/extend/helper.ts	Converts from default export to named exports for testing
test/generators/extend.test.ts	Updates test assertions to match new import patterns

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[coderabbitai]

Walkthrough

Introduces per-file import construction in ExtendGenerator by detecting default vs. named exports via a new helper. Updates test fixture helper to use named exports. Adjusts generator tests to assert on generated import statements (star vs. default) rather than raw paths.

Changes

Cohort / File(s)	Summary of changes
Import construction logic in generator src/generators/extend.ts	Added private helper hasExportWithoutDefault(filePath) to detect absence of default export. ExtendGenerator now computes useImportStar per file and passes it as a fourth argument to utils.getImportStr, altering import strings based on export style.
Test fixture: helper exports switched to named test/fixtures/app/app/extend/helper.ts	Replaced default-exported helper object with two named functions: isCool and isNotCool. Removed export default helper.
Generator tests updated for import assertions test/generators/extend.test.ts	Updated expectations to check for generated import statements: import * as ExtendIHelper from '../../../app/extend/helper' and import ExtendUnittestApplication from '../../../app/extend/application.unittest' instead of raw module paths.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  participant EG as ExtendGenerator
  participant FS as File System
  participant U as utils.getImportStr
  participant Out as Generated Declarations

  EG->>FS: Read target file
  EG->>EG: hasExportWithoutDefault(filePath)
  alt No default export detected
    EG->>U: getImportStr(path, alias, type, useImportStar=true)
  else Default export present
    EG->>U: getImportStr(path, alias, type, useImportStar=false)
  end
  U-->>EG: Import statement string
  EG->>Out: Write import + context
  note over Out: Output varies between<br/>import * as X ... vs. import X ...

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• feat: support gen ts defines on esm project #115 — Also modifies import-string generation (ESM import construction), likely touching getImportStr behavior used here.

Poem

A hare with specs and tidy paws,
Sniffs exports, learns the laws—
“Star or default? I’ll know per file!”
It twitches code with careful style.
Tests now cheer, imports spar—
Hop, hop, shipped! import * as star ✨🐇

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title “feat: support ESM export for extend” succinctly captures the primary enhancement of detecting and supporting named ESM exports in the extend generator, directly reflecting the core change without extraneous details.

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d55a1c0 and 0325854.

📒 Files selected for processing (3)

• src/generators/extend.ts (2 hunks)
• test/fixtures/app/app/extend/helper.ts (1 hunks)
• test/generators/extend.test.ts (2 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

test/fixtures/app/app/extend/helper.ts (1)

test/fixtures/app/app/extend/application.ts (2)

• isCool (2-4)
• isNotCool (6-8)

🔇 Additional comments (4)

test/fixtures/app/app/extend/helper.ts (1)

1-7: Named helper exports align with new generator logic.

Switching the fixture to named exports mirrors the ESM scenario we want to support and keeps the helper surface straightforward for the tests.

test/generators/extend.test.ts (2)

52-54: Great coverage for the star-import path.

This assertion will flag any regression that accidentally falls back to default imports for named-export helpers.

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61-63: Default-import regression guard still in place.

Thanks for keeping a check that the default-export path continues to emit the expected default import.

src/generators/extend.ts (1)

9-12: Import strategy helper looks good.

Centralizing the export detection and passing the flag into getImportStr keeps the generator tidy while enabling the ESM case.

Also applies to: 50-51

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