fix(esm): emit Node-resolvable ESM by switching to nodenext

[evans-sam]

Summary

Fixes `ERR_MODULE_NOT_FOUND` for pure-Node ESM consumers of `fetch-soap`. The published `lib/` previously contained extensionless relative imports (e.g. `import { Client } from './client'`) because tsconfig used `moduleResolution: bundler`. Node's ESM resolver requires explicit `.js` extensions, so any consumer doing `import 'fetch-soap'` from a pure-Node ESM context failed. Bundler-based consumers (webpack, rollup, Next.js) didn't see this because bundlers tolerate extensionless imports.

What changed

• `tsconfig.json`: `module` and `moduleResolution` switched to `nodenext`.
• All relative imports/exports under `src/` now carry explicit `.js` extensions.
• `src/http.ts`: package.json import gained `with { type: 'json' }` — required by nodenext for JSON imports. Supported in Node 18.20+, 20.10+, 22+.
• `src/client.ts`: `eventemitter3` switched to a named import. Nodenext's stricter ESM resolution otherwise treats the `.mjs` default as a module namespace (TS2507).

No behavior changes. Sources still typecheck and the build still emits a `lib/` tree with the same shape — just with importable filenames.

Repro / verification

Before the fix:
```
$ npm ci && npm run build
$ node --input-type=module -e "import * as soap from './lib/soap.js'; console.log(Object.keys(soap))"
Error [ERR_MODULE_NOT_FOUND]: Cannot find module '.../lib/client'
```

After the fix the same command prints all 10 expected keys, and every subpath export declared in `package.json` (`./security`, `./client`, `./wsdl`, `./http`, `./types`) loads cleanly under Node ESM.

Reviewer notes

• Engines field is currently `>=18.0.0`. Strictly speaking, the new JSON import attribute (`with { type: 'json' }`) is only supported on Node 18.20+ for the 18.x line. Worth bumping in a follow-up if precision matters; not done here.
• `test/` was intentionally not touched. `npm test` currently fails because the test files use CJS `require()` in a `"type": "module"` package — preexisting and presumably handled by the in-flight Bun migration (`plans/2026-04-16-bun-migration.md`).

Test plan

• CI build passes
• `npm run build && node --input-type=module -e "import * as soap from './lib/soap.js'; console.log(Object.keys(soap))"` prints keys (no `ERR_MODULE_NOT_FOUND`)
• Each subpath export under `package.json#exports` is importable from a Node ESM consumer

Summary by CodeRabbit

• Refactor
  • Updated module imports to use explicit file extensions and ESM-compatible paths across the codebase.
  • Adjusted TypeScript compiler configuration for improved module resolution standards.

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR updates TypeScript configuration and import statements across the codebase to explicitly include .js file extensions and use ESM-style module resolution. Configuration changes from ESNext/bundler to nodenext for both module and moduleResolution settings.

Changes

Cohort / File(s)	Summary
TypeScript Configuration tsconfig.json	Module system changed from ESNext to nodenext and moduleResolution from bundler to nodenext to align with ESM module resolution standards.
Core Client & SOAP Module src/client.ts, src/soap.ts	Import specifiers updated with .js extensions (./http.js, ./types.js, ./utils.js, ./wsdl/index.js, etc.); named import for EventEmitter from eventemitter3; re-exports adjusted to match new specifiers.
HTTP & Type Utilities src/http.ts, src/types.ts, src/utils.ts	Import paths updated to use explicit .js extensions; JSON module assertion added to package.json import in http.ts.
Security Module src/security/BasicAuthSecurity.ts, src/security/BearerSecurity.ts, src/security/WSSecurity.ts, src/security/index.ts	All import specifiers updated with .js extensions; re-export paths in index.ts adjusted to reference .js files.
WSDL Module src/wsdl/elements.ts, src/wsdl/index.ts	Import specifiers updated with .js extensions for all internal and sibling module references.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related issues

• Published lib/ uses extensionless ESM imports; pure Node consumers hit ERR_MODULE_NOT_FOUND #43: The changes directly address the published-lib extensionless-ESM resolution issue by adding explicit .js extensions across all imports and updating tsconfig to use nodenext module resolution.

Poem

🐰 Extensions sprouting in each import line,
From .js whispers, modules align,
nodenext paths through forests we roam,
ESM standards bring clarity home! 📦✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately captures the main change: converting to Node-resolvable ESM via the nodenext TypeScript configuration, with explicit .js extensions and import syntax updates throughout the codebase.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ 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 claude/gallant-swanson-aff4d0

---

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/http.ts`:
- Line 14: The JSON import uses the newer "with { type: 'json' }" attribute
which breaks Node 18.0–18.19; replace that import so package.json is loaded in a
Node-18.0+ compatible way (e.g., read and parse the file at runtime) instead of
using the JSON import attribute. Locate the problematic import line referencing
package.json in src/http.ts (the import statement using "with { type: 'json' }")
and change it to load package.json via a runtime read/parse approach (for
example using fs.readFileSync/new URL(import.meta.url) and JSON.parse or
createRequire) and assign the result to the same symbol (pkg) so all references
to pkg in functions such as any logic in this module continue to work.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7f85ffc3-c77d-4c63-829f-61842bd04b83

📥 Commits

Reviewing files that changed from the base of the PR and between 6f4460a and 2231649.

📒 Files selected for processing (12)

• src/client.ts
• src/http.ts
• src/security/BasicAuthSecurity.ts
• src/security/BearerSecurity.ts
• src/security/WSSecurity.ts
• src/security/index.ts
• src/soap.ts
• src/types.ts
• src/utils.ts
• src/wsdl/elements.ts
• src/wsdl/index.ts
• tsconfig.json