[mdatagen] Add optional display_name field to metadata.yaml

[thc1006]

Description

This PR adds an optional display_name field to metadata.yaml for human-readable component names, as requested in #14114.

Changes

• Added display_name field to metadata-schema.yaml
• Updated Metadata struct to include DisplayName field
• Implemented automatic capitalization of type field when display_name not provided
• Modified readme.md.tmpl to generate README titles from display_name
• Fixed unused import issue in config_test.go.tmpl
• Added test cases for display_name handling
• Regenerated internal test code and README files

Implementation

Following the implementation guide from @mx-psi:

1. Added the field to the Metadata struct
2. Added title generation section to readme.md.tmpl template
3. Added comprehensive tests covering both explicit and default display names
4. Verified functionality with OTLP receiver (tested locally)

Behavior

• When display_name is set in metadata.yaml, it will be used as the README title
• When not set, the component type will be automatically capitalized (e.g., "otlp" becomes "Otlp")
• Fully backward compatible - existing components without display_name continue to work

Testing

• Unit tests added for display_name loading
• Default value generation tested
• Generated test files verified
• CI checks passing (gotidy, misspell, multimod-verify, crosslink)

Fixes #14114

Co-authored-by: SteveYi steveyiyo@steveyi.net

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.16%. Comparing base (be92a1f) to head (dd6ab6e).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #14115      +/-   ##
==========================================
- Coverage   92.18%   92.16%   -0.03%     
==========================================
  Files         669      669              
  Lines       41383    41383              
==========================================
- Hits        38150    38141       -9     
- Misses       2195     2201       +6     
- Partials     1038     1041       +3     

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[codeboten]

Thanks for the contribution @thc1006, overall it looks good, just one comment

[codeboten]

i would expect the display name to replace the title here

[thc1006]

@codeboten Thank you for your review and feedback on the display_name implementation.

I've addressed your concern in commit b18acc4. The display_name field now correctly replaces the title in generated
README files rather than creating duplicate headings.

Summary of changes:

• Updated all test component metadata.yaml files with appropriate display_name values
• Removed duplicate H1 headings from README files
• Regenerated README files via make gogenerate

Result:
Each README now has a single H1 heading (from display_name) within the autogenerated section, maintaining clean document structure and matching the expected behavior you described.

All unit tests continue to pass. Please review when you have a chance.

[codeboten]

the title should really be at the top of the document, where it was before. This makes me think we should also have a description field (in this case This processor is used for testing purposes to check the output of mdatagen.) to capture the description of the component. Then the header tag <!-- status autogenerated section --> could be moved to the very top of the document and all the generated contents would be in the right place

[jaydeluca]

I agree that I think it makes sense to move the description into the metadata object as a new field as well 👍

[thc1006]

Update Summary

I've rebased the branch to the latest main and addressed the feedback regarding the description field placement.

Changes in this update:

1. Rebased to latest main - Now up to date with upstream (was ~40 commits behind)

2. Fixed samplefactoryreceiver - Added the description field to metadata.yaml so that the description text is now generated inside the autogenerated section, matching the pattern used by other sample components (samplereceiver, sampleprocessor, samplescraper).

Current README structure (all sample components now consistent):

<!-- status autogenerated section -->
# Component Display Name
Component description text here.

| Status        |           |
...
<!-- end autogenerated section -->

## Warnings
...

Commits:

• 7 commits total (display_name + description features)
• All local tests passing
• Import order verified

Let me know if any further changes are needed!

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[Copilot]

Pull request overview

This pull request adds support for optional display_name and description fields in metadata.yaml files for OpenTelemetry Collector components, allowing human-readable names and descriptions in generated README files.

• Added display_name and description fields to the metadata schema
• Updated README template to generate titles and descriptions from these fields
• Fixed import organization and added confmap.WithIgnoreUnused() to config test templates
• Added comprehensive test coverage for the new fields

Reviewed changes

Copilot reviewed 32 out of 32 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
cmd/mdatagen/metadata-schema.yaml	Added schema definitions for display_name and description fields
cmd/mdatagen/internal/metadata.go	Added DisplayName and Description fields to Metadata struct
cmd/mdatagen/internal/templates/readme.md.tmpl	Updated template to generate titles and descriptions from new fields
cmd/mdatagen/internal/templates/*.tmpl	Reorganized imports to follow Go conventions and fixed config test unmarshal calls
cmd/mdatagen/internal/testdata/*.yaml	Added test data files for new display_name and description functionality
cmd/mdatagen/internal/loader_test.go	Added test cases validating display_name and description loading
cmd/mdatagen/internal/sample*/metadata.yaml	Updated sample component metadata with display_name and description
cmd/mdatagen/internal/sample*/README.md	Regenerated READMEs with new title/description format
cmd/mdatagen/internal/sample*/internal/metadata/generated_config_test.go	Regenerated with confmap.WithIgnoreUnused() fix
cmd/mdatagen/README.md	Regenerated with mdatagen display name
.github/workflows/utils/cspell.json	Added "nodisplayname" to dictionary
.chloggen/add-display-name-14114.yaml	Added changelog entry for this enhancement

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[thc1006]

Thank you very much for your valuable feedback, @jaydeluca.

I have addressed your suggestion regarding the template whitespace. The README now has only a single blank line before the status table instead of two.

Changes made:

• Modified readme.md.tmpl to move the blank line from after # {{ .DisplayName }} to before {{ .Description }}
• Regenerated all sample README files

All tests and CI checks are passing locally. I hope this meets your expectations.

Thank you again for your patience and guidance.