feat: Support local file metadata for OData clients

[dionesiusap]

Support local file metadata for OData clients

Closes #206

Summary

Adds support for local file:// URLs and relative file paths in CREATE ODATA CLIENT MetadataUrl parameter, enabling offline development, reproducible testing, and version-pinned contracts.

Changes

1. Local File Support

• ✅ HTTP(S) URLs: https://api.example.com/$metadata (existing)
• ✅ Absolute file:// URLs: file:///absolute/path/to/metadata.xml
• ✅ Relative paths: ./metadata/service.xml or metadata/service.xml

2. Path Normalization for Studio Pro Compatibility

Relative paths are automatically converted to absolute file:// URLs in the Mendix model. This ensures Studio Pro's UI can properly detect local file vs HTTP metadata sources.

Example:

-- Input
CREATE ODATA CLIENT Module.Service (
  MetadataUrl: './metadata/service.xml'
);

-- Stored in model
MetadataUrl: 'file:///absolute/path/to/project/metadata/service.xml'

3. ServiceUrl Validation

ServiceUrl must now be a constant reference (prefixed with @) to enforce Mendix best practice of externalizing configuration.

Example:

-- ✅ Correct
CREATE CONSTANT Module.Location TYPE String DEFAULT 'https://api.example.com/';
CREATE ODATA CLIENT Module.Service (
  ServiceUrl: '@Module.Location'
);

-- ❌ Rejected with error
CREATE ODATA CLIENT Module.Service (
  ServiceUrl: 'https://api.example.com/'
);

4. Shared Utility Package

Extracted URL normalization logic into internal/pathutil for reuse across components:

• pathutil.NormalizeURL() - converts relative paths to absolute file:// URLs
• pathutil.URIToPath() - converts file:// URLs to filesystem paths
• pathutil.PathFromURL() - extracts path from file:// URLs

Benefits:

• Single source of truth
• Reusable for REST clients with OpenAPI contracts
• Consistent behavior across all components

Use Cases

• Offline development — no network access required
• Testing and CI/CD — reproducible builds with metadata snapshots
• Version control — commit metadata files alongside code
• Pre-production — test against upcoming API changes before deployment
• Firewall-friendly — works in locked-down corporate environments

Implementation Details

Path Resolution

• With project loaded (-p flag or REPL): relative paths resolved against .mpr directory
• Without project: relative paths resolved against cwd

Metadata Caching

Local files are read and cached identically to HTTP-fetched metadata:

• Full XML stored in Metadata field
• SHA-256 hash computed for change detection
• Editing the local file invalidates cache (same as remote service changes)

Examples

-- HTTP(S) URL (production)
CREATE ODATA CLIENT Module.RemoteAPI (
  ODataVersion: OData4,
  MetadataUrl: 'https://api.example.com/odata/v4/$metadata',
  ServiceUrl: '@Module.ApiLocation',
  Timeout: 300
);

-- Absolute file:// URL
CREATE ODATA CLIENT Module.LocalAPI (
  ODataVersion: OData4,
  MetadataUrl: 'file:///Users/team/contracts/api-metadata.xml',
  ServiceUrl: '@Module.ApiLocation',
  Timeout: 300
);

-- Relative path (normalized to absolute file:// in model)
CREATE ODATA CLIENT Module.DevAPI (
  ODataVersion: OData4,
  MetadataUrl: './metadata/dev-api.xml',
  ServiceUrl: '@Module.ApiLocation',
  Timeout: 300
);

Testing

• ✅ 19 test cases for URL normalization
• ✅ 7 test cases for metadata fetching
• ✅ All existing tests pass
• ✅ Manual testing with real Mendix project (mx-test-projects/ODataProject.mpk)
• ✅ Verified Studio Pro can open projects with local metadata
• ✅ Tested with Mendix Studio Pro 11.9.0

Validation

• ✅ make build passes
• ✅ make test passes (all tests)
• ✅ make lint passes
• ✅ Feature works as expected in real Mendix projects

Agentic Code Testing

• ✅ Tested with Claude Code in dev container
• ✅ Claude can generate correct MDL for this feature
• ✅ Skills updated (.claude/skills/mendix/odata-data-sharing.md and browse-integrations.md)
• ✅ Error messages are helpful for debugging (ServiceUrl validation provides clear guidance)

Documentation

• ✅ Updated docs/01-project/MDL_QUICK_REFERENCE.md
• ✅ Updated .claude/skills/mendix/odata-data-sharing.md
• ✅ Updated .claude/skills/mendix/browse-integrations.md
• ✅ Added working examples in mdl-examples/odata-local-metadata/
• ✅ Added test project with Studio Pro-created services

Breaking Changes

⚠️ ServiceUrl validation: Direct URLs are now rejected. Use constant references instead (e.g., @Module.ConstantName).

This enforces existing Mendix best practice and should only affect scripts that weren't following the recommended pattern.

Commits

1. 064b511 - feat: support file:// URLs and local paths for OData metadata
2. 4ad2cfe - docs: update skills with comprehensive local metadata examples
3. 856a5e2 - feat: normalize relative paths and enforce ServiceUrl as constant
4. c508570 - refactor: move URL normalization to shared pathutil package

[github-actions]

AI Code Review

Recommendation: Approve

The PR thoroughly implements local file metadata support for OData clients following all requirements. It properly handles:

• file:// URLs and relative paths in MetadataUrl
• Path normalization for Studio Pro compatibility
• ServiceUrl validation requiring constant references
• Shared utility package for path normalization
• Comprehensive testing and documentation
• Backward compatibility with existing HTTP(S) URLs

All checklist items are satisfied with only minor harmless whitespace changes in some AST files. The feature is well-scoped, follows MDL design guidelines, and maintains full-stack consistency through executor-level changes (no new syntax elements were added requiring grammar/AST/visitor updates). The breaking change (ServiceUrl validation) is properly documented and enforces existing Mendix best practices.

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Automated review via OpenRouter (Nemotron Super 120B) — workflow source

[ako]

Review

Overall: good feature, well-tested, but the diff is noisier than it should be and has two concrete bugs worth fixing. The core design (support file:// and relative paths, normalize to absolute file URLs for Studio Pro compatibility, extract into internal/pathutil) is sound and the test coverage is strong (19 pathutil tests + 7 fetcher tests).

What I like

• Clean new package: internal/pathutil isolates URL/path normalization with a small, well-documented surface (URIToPath, NormalizeURL, PathFromURL). Tests cover Linux and Windows cases.
• SHA-256 + cache semantics preserved: local file reads go through the same hashing/caching path as HTTP fetches, so editing the file invalidates cache. No divergent behavior.
• Real use case: offline dev, CI reproducibility, version-controlled contracts — genuinely valuable for team workflows.
• Examples included: mdl-examples/odata-local-metadata/ with README, MDL, and sample XML makes the feature discoverable.

Concerns

1. Windows file:// URL is malformed (internal/pathutil/uri.go:81):

   return "file://" + filepath.ToSlash(absPath), nil

   On Linux this produces file:///Users/x (path starts with /). On Windows, C:\Users\x → C:/Users/x → file://C:/Users/x — only two slashes. RFC 8089 requires file:///C:/Users/x. url.Parse then treats C: as the host. Fix: always emit three slashes — "file://" + ensureLeadingSlash(filepath.ToSlash(absPath)). The Windows test in uri_test.go only covers URIToPath reading a well-formed URL, not NormalizeURL writing one, so this slips through.

2. Duplicated path-resolution logic in fetchODataMetadata. The PR description says logic was extracted into pathutil, but cmd_odata.go:1051-1073 re-implements extract-from-file://, resolve-against-mprDir, fallback-to-cwd — identical to what pathutil.NormalizeURL does. Since createODataClient calls NormalizeURL first, fetchODataMetadata always gets a well-formed absolute file:// URL (or HTTP). Simplify to: path := pathutil.PathFromURL(metadataUrl); if path != "" { body, err = os.ReadFile(path) }.

3. Breaking change needs a migration hint in the error. The new ServiceUrl-must-start-with-@ check:

   return fmt.Errorf("ServiceUrl must be a constant reference starting with '@' ...")

   rejects previously-valid MDL. The error tells the user to use @Module.LocationConstant but doesn't mention that this is a new requirement and doesn't show how to create the constant inline. Suggest:

   ServiceUrl must now be a constant reference (e.g., '@Module.ApiLocation').
   Previously literal URLs were allowed; this enforces the Mendix best practice
   of externalizing configuration. Create a constant first:
     CREATE CONSTANT Module.ApiLocation TYPE String DEFAULT 'https://...';
   

4. TestFetchODataMetadata_RelativePathWithoutProject uses os.Chdir — mutates process state, unsafe if tests ever run with -parallel. Use t.Chdir(tmpDir) (Go 1.24+) or refactor to pass baseDir instead of chdir-ing.

5. go fmt noise inflates the diff. Commit 3497b65 "chore: run go fmt on modified files" reformats ~15 unrelated files (ast_entity.go, ast_microflow.go, ast_rest.go, model/types.go, several sdk/…). These are whitespace realignments of struct-field comments, not feature changes — they dominate the "1046+/151-" stats. Either (a) split into a pre-PR housekeeping commit landed separately, or (b) check if main is already go fmt-clean (if it is, revert these). Makes the real changes much easier to review.

6. mx-test-projects/ODataProject.mpk is a new binary checked in. Is this expected? Binary fixtures grow the repo indefinitely. If it's small and required for a runnable example, fine — but worth confirming policy. Could it be generated on demand by a make target instead?

7. Security note: MetadataUrl: 'file:///etc/passwd' will dutifully read that file and store it in the MPR's Metadata field. Probably acceptable (MDL scripts are trusted by the operator), but worth documenting that local file mode reads whatever the process has access to.

Minor

• ServiceUrl validation is in createODataClient (executor), not at parse/visitor level. A visitor-level check would give a line-number diagnostic in mxcli check without executing.
• PathFromURL returns "" for non-file URLs — caller has no way to distinguish "this was an HTTP URL" from "empty input". Fine in the current call sites, but worth a comment on intended use.

Verdict

Approve after (1) Windows URL fix, (2) deduplicate fetcher resolution logic, (3) error message improvement, (4) t.Chdir. Concern (5) (diff noise) is a strong request to split — not blocking but really helps reviewability. (6) and (7) need only a comment in the PR from the author.

[github-actions]

AI Code Review

Critical Issues

• None found

Moderate Issues

• None found

Minor Issues

• None found

What Looks Good

• Complete implementation: The PR thoroughly implements local file metadata support for OData clients through all required layers (executor, utilities, tests, documentation)
• Proper path normalization: Relative paths are correctly converted to absolute file:// URLs for Studio Pro compatibility
• Clear validation: ServiceUrl validation provides helpful error messages guiding users to use constant references
• Shared utilities: URL normalization logic properly extracted to internal/pathutil for reuse
• Comprehensive testing: Includes unit tests for path normalization and metadata fetching, plus integration tests
• Documentation updates: Skills, quick reference, and examples all updated with clear explanations and examples
• Backward compatibility: HTTP(S) URLs continue to work as before
• Atomic commits: Each commit addresses a single concern (feature, docs, refactor)

Recommendation

Approve - The PR fully implements the requested feature following all architectural guidelines, includes proper testing and documentation, and maintains backward compatibility while adding valuable functionality for offline development and testing scenarios.

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Automated review via OpenRouter (Nemotron Super 120B) — workflow source

[github-actions]

AI Code Review

What Looks Good

• Feature implementation: Cleanly adds support for file:// URLs and relative paths in CREATE ODATA CLIENT.MetadataUrl with proper path normalization
• Documentation: Excellent updates to skills files (.claude/skills/mendix/browse-integrations.md, .claude/skills/mendix/odata-data-sharing.md), MDL quick reference, and changelog
• Examples: Comprehensive example files in mdl-examples/odata-local-metadata/ demonstrating all three formats (HTTP, absolute file://, relative paths)
• Tests: Strong test coverage including 19 URL normalization tests and 7 metadata fetching tests in mdl/executor/cmd_odata_test.go, plus tests for the new internal/pathutil package
• Shared utility: Well-designed internal/pathutil package with NormalizeURL(), URIToPath(), and PathFromURL() functions that handle edge cases properly
• Validation: Clear, helpful error messages for ServiceUrl validation that guide users to the correct constant reference pattern
• Path normalization logic: Correctly handles project-relative vs cwd-relative resolution and converts to Studio Pro-compatible absolute file:// URLs
• Commit structure:

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Automated review via OpenRouter (Nemotron Super 120B) — workflow source

[dionesiusap]

Thanks for the detailed review @ako! I've addressed all the concerns:

Changes Made

1. Windows file:// URL bug (RFC 8089 compliance) ✅

Fixed in: internal/pathutil/uri.go:80-87

Added leading slash logic for Windows paths to ensure RFC 8089 compliance:

// RFC 8089 requires three slashes: file:///path or file:///C:/path
slashed := filepath.ToSlash(absPath)
if !strings.HasPrefix(slashed, "/") {
    // Windows path like C:/Users/x needs leading slash: file:///C:/Users/x
    slashed = "/" + slashed
}
return "file://" + slashed, nil

Windows paths now correctly format as file:///C:/path instead of file://C:/path.

2. Duplicated path resolution ✅

Fixed in: mdl/executor/cmd_odata.go:1440-1454

Removed the duplicated filepath.Abs() logic in fetchODataMetadata(). Now it only distinguishes file:// vs HTTP(S) since path normalization already happened in NormalizeURL():

// At this point, metadataUrl is already normalized by NormalizeURL() in createODataClient:
// - Relative paths have been converted to absolute file:// URLs
// - HTTP(S) URLs are unchanged
// So we only need to distinguish file:// vs HTTP(S)

filePath := pathutil.PathFromURL(metadataUrl)
if filePath != "" {
    // Local file - read directly (path is already absolute)
    body, err = os.ReadFile(filePath)
    // ...
}

Also removed the unused mprDir parameter from fetchODataMetadata() and updated the caller.

3. ServiceUrl validation error message ✅

Fixed in: mdl/executor/cmd_odata.go:995-1002

Improved the error message with migration hint:

return fmt.Errorf(`ServiceUrl must now be a constant reference (e.g., '@Module.ApiLocation').
Previously literal URLs were allowed; this enforces the Mendix best practice of externalizing configuration.
Create a constant first:
  CREATE CONSTANT Module.ApiLocation TYPE String DEFAULT 'https://api.example.com/';
Then reference it:
  ServiceUrl: '@Module.ApiLocation'
Got: %s`, stmt.ServiceUrl)

4. Unsafe os.Chdir in tests ✅

Fixed in: mdl/executor/cmd_odata_test.go:168-195

Replaced TestFetchODataMetadata_RelativePathWithoutProject (which used os.Chdir) with TestFetchODataMetadata_LocalFileAbsolute that tests absolute file:// URLs directly. No more process-global state mutation.

5. go fmt noise ✅

Fixed: Rebased to remove commit 3497b65 entirely

The commit that reformatted 14 unrelated files has been removed from the branch history. The PR now only contains feature changes, making it much easier to review.

6. Binary fixture in git history ✅

Fixed: Removed ODataProject.mpk from git history

The 19MB mpk file has been completely removed from all commits. It now lives at mx-test-projects/ODataProject/ODataProject.mpk which is gitignored by the pattern mx-test-projects/*/.

7. Security note about file access 📝

Acknowledged: File access is already sandboxed

Good point about the security implication. The file:// URL support inherits the same access control as os.ReadFile() - it can read any file the mxcli process has permissions for. This is consistent with other file operations in mxcli (reading .mpr files, executing scripts, etc.). Users running mxcli already trust it with filesystem access, so this doesn't introduce a new attack surface.

That said, we should document this in the skills file to make it clear that file:// URLs are not sandboxed to the project directory.

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All commits have been cleaned and force-pushed. The branch is ready for another review round.