HttpCodec header constructor based on Schema

[987Nabil]

Should work the same as with query params.
I was thinking that we could even do an equivalent to queryAll that takes a case class and looks up all headers that correlate with the field names.

[jdegoes]

/bounty $750

[algora-pbc]

💎 $750 bounty • ZIO

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1. Start working: Comment /attempt #3232 with your implementation plan
2. Submit work: Create a pull request including /claim #3232 in the PR body to claim the bounty
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Attempt	Started (GMT+0)	Solution
🔴 @987Nabil	Dec 4, 2024, 3:12:32 PM	#3270
🟡 @PastSmartLink	Jan 2, 2025, 12:58:52 PM	WIP

[987Nabil]

/attempt #3232

Algora profile	Completed bounties	Tech	Active attempts	Options
@987Nabil	99 ZIO bounties + 4 bounties from 2 projects	Scala		Cancel attempt

[algora-pbc]

@987Nabil: Reminder that in 7 days the bounty will become up for grabs, so please submit a pull request before then 🙏

[algora-pbc]

The bounty is up for grabs! Everyone is welcome to /attempt #3232 🙌

[987Nabil]

It turns out we need here more complex changes. I'll keep working on it. Might take a while.

[PastSmartLink]

Comment /attempt #3232 # Implementation Plan: HttpCodec Header Constructor Based on Schema (#3232)

Objective

Enhance HttpCodec to support constructing headers based on a provided schema, similar to how query parameters are handled. Additionally, provide functionality to map headers to a case class.

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Steps to Implement

1. Analyze Existing Code

• Review the current implementation of HttpCodec for query parameters and headers.
• Understand how query parameters map to schemas and case classes.
• Identify reusable components and potential changes for header support.

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2. Design Schema Integration for Headers

• Define a mechanism for associating HTTP headers with schema fields.
• Ensure that field names in the schema map correctly to header names (consider case-insensitivity for headers).
• Support custom header name mappings using annotations or similar mechanisms.

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3. Implement Header-to-Schema Mapping

• Extend HttpCodec to parse headers based on a schema.
  • Add a method fromHeaders(schema: Schema[T]): HttpCodec[T] to construct a codec for headers.
  • Parse headers from the request into the corresponding fields of the schema.
• Implement error handling for missing or invalid headers.

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4. Add queryAll Equivalent for Headers

• Create a method headerAll[T](schema: Schema[T]): HttpCodec[T].
  • Collect all headers matching the field names in the schema.
  • Populate a case class instance with the values from the headers.

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5. Testing

Unit Tests

• Write unit tests for the new header-to-schema mapping functionality.
• Test various scenarios, including:
  • Exact field-to-header name matches.
  • Custom header name mappings.
  • Missing or invalid headers.

Integration Tests

• Validate that the new functionality integrates seamlessly with existing HttpCodec features.
• Test with real HTTP requests and responses.

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6. Documentation

• Update the project documentation to include:
  • Usage examples for the new header constructor based on schema.
  • Guidelines on using the headerAll method.
• Add comments in the code to explain the new methods and their functionality.

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7. Code Review and Refinement

• Submit a pull request with the implementation and include /claim #3232 in the PR body.
• Address any feedback from the maintainers and the community.

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Optional Enhancements

• Provide support for custom header value transformations (e.g., decoding/encoding).
• Implement caching or optimization for schema lookups if performance becomes a concern.
• Add utilities for case-insensitive schema mappings.

---

Timeline

1. Day 1-2: Analyze existing code and design the schema integration for headers.
2. Day 3-5: Implement the core functionality and unit tests.
3. Day 6-7: Write integration tests and documentation.
4. Day 8: Submit the pull request and address initial feedback.

---

Deliverables

1. Updated HttpCodec with header-to-schema functionality.
2. Comprehensive unit and integration tests.
3. Updated documentation and usage examples.

---

Note: Ensure code adheres to the project's contribution guidelines and coding standards.

Options

• Cancel my attempt

[987Nabil]

@PastSmartLink Please read my last message. I am still working on it and we need a redesign. This is discussed with @jdegoes and you will waste your time working on this.

[algora-pbc]

@PastSmartLink: Reminder that in 7 days the bounty will become up for grabs, so please submit a pull request before then 🙏

[algora-pbc]

💡 @987Nabil submitted a pull request that claims the bounty. You can visit your bounty board to reward.