Refactor: Introduce standardized RESTError and QueryError types

[lowhung]

Description

This PR refactors the REST handler error handling to use RESTError consistently instead of anyhow. This takes the work from QueryError in the state modules and creates what I think is a better error handling flow.

Changes:

• Updated all handler function signatures from Result<RESTResponse> to Result<RESTResponse, RESTError>
• Updated query_state closures to return QueryError instead of wrapping in anyhow
• Added proper error conversion from QueryError to RESTError via the From trait
• Standardized parameter validation using RESTError::invalid_param(), RESTError::param_missing(), etc.

Related Issue(s)

Part of #313

How was this tested?

• Code builds successfully
• Existing unit tests pass
• Manual testing of some endpoints (if applicable)

Checklist

• My code builds and passes local tests
• CI is green for this PR

Impact / Side effects

Error responses maintain the same HTTP status codes and structure.

[Copilot]

Pull Request Overview

This PR standardizes error handling across REST endpoints by introducing RESTError and updating QueryError types. The changes eliminate anyhow::Result in favor of strongly-typed error handling, providing more consistent HTTP status codes and error messages.

Key changes:

• Handler signatures updated from Result<RESTResponse> to Result<RESTResponse, RESTError>
• Query state closures now return QueryError instead of wrapping errors in anyhow
• Standardized parameter validation using RESTError::invalid_param(), RESTError::param_missing(), etc.

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
modules/spdd_state/src/rest.rs	Updated SPDD handler to use RESTError
modules/rest_blockfrost/src/rest_blockfrost.rs	Updated handler registration signatures and cleaned up imports
modules/rest_blockfrost/src/handlers/pools.rs	Refactored pool handlers to use RESTError with proper error conversion
modules/rest_blockfrost/src/handlers/governance.rs	Updated governance handlers to use RESTError and standardized message bus error handling
modules/rest_blockfrost/src/handlers/epochs.rs	Updated epoch handlers with RESTError and improved error messages
modules/rest_blockfrost/src/handlers/blocks.rs	Simplified block handlers by removing QueryError::NotFound handling
modules/rest_blockfrost/src/handlers/assets.rs	Refactored asset handlers to use RESTError consistently
modules/rest_blockfrost/src/handlers/addresses.rs	Updated address handlers with RESTError and improved error context
modules/rest_blockfrost/src/handlers/accounts.rs	Refactored account handlers with RESTError and improved error handling
modules/drdd_state/src/rest.rs	Updated DRDD handler to use RESTError with storage_disabled check
common/src/rest_helper.rs	Updated REST helper functions to handle RESTError properly
common/src/rest_error.rs	Fixed param_missing message format
common/src/queries/utils.rs	Updated query_state and rest_query_state to use QueryError
common/src/queries/errors.rs	Added Fromanyhow::Error implementation for QueryError

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[Copilot]

Pull Request Overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

modules/rest_blockfrost/src/handlers/accounts.rs:534

• This error handling wasn't updated to use the new error pattern. It should be:

let json = serde_json::to_string_pretty(&rest_response)?;
Ok(RESTResponse::with_json(200, &json))

This is inconsistent with the rest of the refactoring where serde_json errors are automatically converted to RESTError via the From trait.

    match serde_json::to_string_pretty(&rest_response) {
        Ok(json) => Ok(RESTResponse::with_json(200, &json)),
        Err(e) => Ok(RESTResponse::with_text(
            500,
            &format!("Internal server error while serializing addresses: {e}"),
        )),
    }

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[whankinsiv]

Nice!

[whankinsiv]

This is also really nice!

[whankinsiv]

Really nice job Matt! I really like how this PR cleans up the parameter parsing and serialization error handling.