feat(terraphim_grep): failover to fff-search enhanced grep when KG is not configured

[AlexMikhalev]

Summary

Makes terraphim-grep usable without a knowledge-graph thesaurus by falling back to fff-search enhanced grep mode. Also bumps the workspace version to 1.21.0.

Changes

• crates/terraphim_grep/Cargo.toml: make code-search a default feature.
• crates/terraphim_grep/src/main.rs: add resolve_thesaurus() helper that returns an empty Thesaurus when no project thesaurus is found.
• crates/terraphim_grep/src/lib.rs: add unit test for empty-thesaurus search.
• crates/terraphim_grep/tests/no_thesaurus_cli.rs: add integration test for CLI invocation without --thesaurus.
• Cargo.toml / crates/terraphim_grep/Cargo.toml: bump workspace version to 1.21.0 and align terraphim_service dependency.

Verification

• cargo test -p terraphim_grep passes.
• cargo clippy -p terraphim_grep -- -D warnings passes.
• Installed terraphim-grep --version reports 1.21.0.
• Manual test: terraphim-grep works in a directory with no .terraphim config.

Related

• Refs terraphim/terraphim-clients#55
• Refs terraphim/terraphim-ai#2995

[AlexMikhalev]

Summary

This PR makes terraphim-grep usable without a knowledge-graph thesaurus by falling back to fff-search enhanced grep mode. It also bumps the workspace version to 1.21.0 so installed binaries align with the latest terraphim-ai release.

Key changes:

• crates/terraphim_grep/Cargo.toml: Moves code-search into default features so the fff-search backend is always available.
• crates/terraphim_grep/src/main.rs: Introduces resolve_thesaurus() which returns an empty Thesaurus when no explicit/default thesaurus exists, instead of failing the CLI.
• crates/terraphim_grep/src/lib.rs: Adds search_without_thesaurus_uses_fff_mode unit test.
• crates/terraphim_grep/tests/no_thesaurus_cli.rs: Adds an integration test that runs the compiled binary without --thesaurus and asserts valid JSON with empty concepts and at least one chunk.
• Workspace version: Bumps to 1.21.0 and aligns the terraphim_service dependency version.

What was done well:

• The failover is automatic and transparent — no new CLI flags required.
• Existing KG-boosted behaviour is preserved when a thesaurus is present.
• Both unit and integration tests cover the new path.
• All tests, clippy, and pre-commit checks pass.

What remains to consider:

• None. The change is additive and the integration test exercises the real binary.

Confidence Score: 5/5

• Safe to merge with minimal risk.
• Zero P0/P1 findings. The failover path reuses existing fff-search integration and an empty Thesaurus constructor that already had test coverage. Version bump is mechanical.
• No files require special attention.

Important Files Changed

Filename	Overview
crates/terraphim_grep/src/main.rs	Replaces hard thesaurus error with resolve_thesaurus() fallback. Clean additive change.
crates/terraphim_grep/Cargo.toml	Adds code-search to default features; bumps terraphim_service version.
crates/terraphim_grep/src/lib.rs	Unit test for empty-thesaurus search.
crates/terraphim_grep/tests/no_thesaurus_cli.rs	Integration test invoking the real binary without a thesaurus.
Cargo.toml	Workspace version bump to 1.21.0.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[terraphim-grep query] --> B{--thesaurus or default?}
    B -->|Yes| C[Load Thesaurus]
    B -->|No| D[Empty Thesaurus]
    C --> E[HybridSearcher]
    D --> E
    E --> F{KG search}
    F -->|Concepts found| G[Boost chunks with KG]
    F -->|No concepts| H[fff-search only]
    G --> I[GrepResult]
    H --> I
    style D fill:#d4edda,stroke:#28a745
    style H fill:#d4edda,stroke:#28a745

Loading

Inline Findings

No findings. The implementation matches the design and the integration test provides end-to-end evidence.

Footer

_{Last reviewed commit: a15f49e | Reviews (1)}

[AlexMikhalev]

Closing in favour of the canonical Gitea PR: https://git.terraphim.cloud/terraphim/terraphim-clients/pulls/56