feat(plugins): extend RpcDriver for BLOB, materialized views, and type mappings

[aesslinger]

Extends the plugin RPC adapter to forward three method categories that were previously unsupported, enabling full feature parity for plugin drivers.

Ref #16

Changes

1. BLOB Methods Forwarded

save_blob_to_file and fetch_blob_as_data_url are now forwarded to plugin drivers via JSON-RPC. The plugin receives the file path and is responsible for writing the file directly (since it runs on the same machine as the host). Plugins that don't implement these methods return -32601 and the host falls back to the existing "not supported" error (no behavioral change for existing plugins).

2. Materialized View Methods Forwarded

get_materialized_views, get_materialized_view_columns, get_materialized_view_definition, and refresh_materialized_view are now forwarded. Same fallback pattern as above.

3. type_mappings Manifest Field

Adds an optional type_mappings: HashMap<String, String> field to PluginManifest. The RpcDriver uses this to resolve map_inferred_type() locally (this method is synchronous and cannot issue an RPC call). Example: a PostgreSQL plugin declares {"DATETIME": "TIMESTAMP", "JSON": "JSONB"}.

Documentation Updates

• plugins/manifest.schema.json: type_mappings field added (fixes validation for plugins using it)
• plugins/PLUGIN_GUIDE.md: All 6 new RPC methods and type_mappings fully documented with params, results, and contracts
• src/types/plugins.ts: type_mappings added to TS PluginManifest interface

Context

These are prerequisite changes for the PostgreSQL plugin migration initiative. Without them, a plugin driver cannot achieve full feature parity with the built-in PostgreSQL driver for BLOB handling, materialized view management, and type inference during paste/import operations.

Testing

• 22 unit tests covering all new forwarding methods (success path + method-not-found fallback for every method)
• All existing tests pass unchanged (cargo test)
• TypeScript compiles cleanly (pnpm tsc --noEmit)
• Backward-compatible: existing plugins without these methods continue to work (graceful -32601 fallback)

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (7 files)

• src-tauri/src/drivers/driver_trait.rs
• src-tauri/src/drivers/mysql/mod.rs
• src-tauri/src/drivers/postgres/mod.rs
• src-tauri/src/drivers/sqlite/mod.rs
• src-tauri/src/plugins/commands.rs
• src-tauri/src/plugins/driver.rs
• src-tauri/src/plugins/manager.rs

Previous Review Summary (commit a95a781)

Current summary above is authoritative. Previous snapshots are kept for context only.

Previous review (commit a95a781)

Status: No Issues Found | Recommendation: Merge

Files Reviewed (7 files)

• src-tauri/src/drivers/driver_trait.rs
• src-tauri/src/drivers/mysql/mod.rs
• src-tauri/src/drivers/postgres/mod.rs
• src-tauri/src/drivers/sqlite/mod.rs
• src-tauri/src/plugins/commands.rs
• src-tauri/src/plugins/driver.rs
• src-tauri/src/plugins/manager.rs

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_{Reviewed by laguna-s-2.1:free · Input: 649.5K · Output: 47.4K · Cached: 1.1M}

[debba]

Hey @aesslinger, thanks a lot for this one. I checked out the branch, read through the whole diff, and ran everything locally. This is really solid work: the fallback behavior is carefully aligned with the trait defaults, the tests verify both the exact payloads sent over RPC and the -32601 fallback paths, and the decision to resolve map_inferred_type() locally through the manifest (since the trait method is synchronous and can't issue an RPC call) is exactly the right call. I also confirmed the forwarding is actually reachable, since plugins can declare materialized_views: true in their capabilities. Full suite is green on the branch for me: 1051 passed, 0 failed.

I also built a small test plugin implementing the new methods (plus a "legacy" variant that returns -32601) and drove it over JSON-RPC stdio with the exact payloads the RpcDriver sends. Everything behaves as advertised, including the graceful degradation for old plugins. Nice job on backward compatibility.

A few things I'd like to see addressed before merge, none of them about the code itself:

1. plugins/manifest.schema.json needs the new field. The schema has additionalProperties: false at the top level, so a plugin declaring type_mappings in its manifest will currently fail validation in the registry tooling. Adding the property to the schema should be enough.

2. PLUGIN_GUIDE.md should document the new surface. The six new RPC methods and the type_mappings manifest field aren't mentioned yet. Since this PR is the prerequisite for the PostgreSQL plugin migration, the guide is the public contract plugin authors will rely on.

3. The description doesn't match the code for save_blob_to_file. The PR says "plugins return base64-encoded data; the host handles file I/O", but the implementation forwards file_path to the plugin and discards the result, so it's the plugin that writes the file. That's a perfectly fine design given the plugin runs on the same machine, but the description (and ideally the guide) should state the actual contract so plugin authors implement the right thing.

Two small nits, take them or leave them: get_materialized_view_columns is the only new method without a fallback test, and the TS PluginManifest interface in src/types/plugins.ts could gain an optional type_mappings field for completeness (the frontend doesn't consume it today, so no urgency). Also a tiny note on the description: it mentions 21 new tests, but I count 13, the other 8 in that filter are pre-existing.

Overall: approve once the schema and docs are updated. Really happy to see the plugin RPC surface reaching parity, this unblocks a lot.

[aesslinger]

Hey @debba, thanks for the thorough review and for actually spinning up a test plugin to verify the behavior — that's awesome.

All 6 items addressed in the latest push:

1. manifest.schema.json updated — Added type_mappings as an optional object property with additionalProperties: { "type": "string" }. Plugins declaring this field will now pass registry validation.

2. PLUGIN_GUIDE.md updated — Added full documentation for:

• All 4 materialized view methods (get_materialized_views, get_materialized_view_columns, get_materialized_view_definition, refresh_materialized_view) with params, result shapes, and fallback behavior
• Both BLOB methods (save_blob_to_file, fetch_blob_as_data_url) with the corrected contract (see below) and example payloads
• A new "Type Mappings" section explaining the manifest field, rules, and a PostgreSQL example

3. Fixed the BLOB contract description — Both the PR description and the PLUGIN_GUIDE now correctly state that the plugin receives file_path and writes the file directly. The host doesn't handle file I/O — this is the right design since the plugin runs locally on the same machine.

4. Added the missing fallback test — rpc_driver_materialized_view_columns_falls_back_when_method_missing now exists. Every new method has both a success test and a -32601 fallback test.

5. TS interface updated — type_mappings?: Record<string, string> added to PluginManifest in src/types/plugins.ts. No frontend code consumes it today, but it's there for completeness and future use.

6. Test count corrected — 22 plugin driver unit tests total (13 new in this PR + 9 pre-existing that were in the filter). Updated the PR description.

Let me know if there's anything else you'd like adjusted.

[debba]

LGTM, @NewtTheWolf is there something related to tabularium?