remove finished plan

PLAN.md

@@ -1,159 +0,0 @@
-# Hover Assertions in Mdtest Framework
-
-## Goal
-
-Add support for hover assertions in the mdtest framework. These assertions will verify the inferred type of an expression at a specific position, similar to how hover works in a language server.
-
-## Current Architecture
-
-### ty_ide hover tests
-- Use `<CURSOR>` marker in test source code (hover.rs:161-167)
-- Call `hover(db, file, offset)` to get type at cursor position (hover.rs:12-50)
-- Use `find_goto_target()` to find the covering AST node (hover.rs:14)
-- Return the inferred type via `SemanticModel` (hover.rs:22-23)
-
-### mdtest framework
-- Parses markdown files with Python code blocks (parser.rs)
-- Supports two assertion types via comments (assertion.rs:242-248):
-  - `# error:` - matches diagnostics
-  - `# revealed:` - matches revealed-type diagnostics
-- Assertions can be:
-  - End-of-line: `x: int = "foo"  # error: [invalid-assignment]`
-  - Preceding line: `# error: [invalid-assignment]\nx: int = "foo"`
-- Matcher logic in matcher.rs compares assertions against diagnostics
-
-## Implementation Plan
-
-### 1. Add new assertion type (assertion.rs)
-**Status:** ✅ Completed
-
-- [x] Add `Hover(&'a str)` variant to `UnparsedAssertion` enum (line 242)
-- [x] Update `from_comment()` to recognize `# hover:` and `# ↓ hover:` (line 253)
-- [x] Add `Hover(HoverAssertion<'a>)` to `ParsedAssertion` enum (line 294)
-- [x] Add `HoverAssertion` struct with column and expected_type fields
-- [x] Add `HoverAssertionParseError` enum
-- [x] Update parsing logic to validate hover assertions (line 267)
-
-### 2. Extend assertion parsing to capture column position
-**Status:** ✅ Simplified approach
-
-- [x] Hover assertions MUST be preceding-line only (not end-of-line)
-- [x] Down arrow must appear immediately before `hover` keyword (e.g., `# ↓ hover:`)
-- [x] Column position determined by whitespace before `#` in comment
-- [x] Calculate TextSize offset from: (target_line_start + down_arrow_column)
-
-### 3. Create CheckOutput enum (matcher.rs)
-**Status:** ✅ Completed
-
-- [x] Add `CheckOutput` enum with `Diagnostic` and `Hover` variants
-- [x] Update `match_file` to accept `&[CheckOutput]` instead of `&[Diagnostic]`
-- [x] Create `SortedCheckOutputs` similar to `SortedDiagnostics`
-- [x] Update matching logic to extract line numbers from CheckOutput variants
-- [x] Implement `Unmatched` trait for `CheckOutput`
-- [x] Update lib.rs to convert diagnostics to `CheckOutput` before matching
-
-### 4. Add hover checking logic (lib.rs)
-**Status:** ✅ Completed
-
-- [x] Add find_covering_node() to locate AST nodes at positions
-- [x] Add infer_type_at_position() using ty_python_semantic (NOT ty_ide)
-- [x] Add generate_hover_outputs() to scan for hover assertions
-- [x] Calculate position from down arrow column in comment
-- [x] Create CheckOutput::Hover with inferred type
-- [x] Integrate into check flow before match_file()
-
-### 5. Update matcher (matcher.rs)
-**Status:** ✅ Completed
-
-- [x] Add placeholder matching logic for `ParsedAssertion::Hover`
-- [x] Implement actual hover matching logic
-- [x] Match hover outputs by comparing inferred type with expected type
-- [x] Handle `@Todo` metadata stripping in hover assertions
-
-### 6. Add tests
-**Status:** ✅ Completed
-
-- [x] Create comprehensive mdtest file with edge cases (hover.md)
-- [x] Add unit tests for hover assertion parsing in ty_test
-
-## Key Design Decisions
-
-1. **Preceding-line only**: Hover assertions make sense only as preceding-line comments, since we need to identify both line and column via the down arrow.
-
-2. **Down arrow syntax**: `# ↓ hover: int` where the arrow column identifies the hover position. This is intuitive and visual.
-
-3. **Reuse diagnostic infrastructure**: By converting hover results to diagnostics, we leverage the existing matcher framework rather than creating parallel logic.
-
-4. **Similar to revealed assertions**: The implementation will closely mirror the `revealed:` assertion logic, as both check inferred types.
-
-## Example Usage
-
-```python
-# Test basic type inference
-a = 10
-    # ↓ hover: Literal[10]
-    a
-
-# Test function type
-def foo() -> int: ...
-       # ↓ hover: def foo() -> int
-       foo
-```
-
-## Files to Modify
-
-1. `crates/ty_test/src/assertion.rs` - Add `Hover` assertion type
-2. `crates/ty_test/src/lib.rs` - Add hover checking logic
-3. `crates/ty_test/src/matcher.rs` - Add hover matching logic
-4. `crates/ty_test/src/diagnostic.rs` - Add hover diagnostic type (if needed)
-5. Tests in existing mdtest files to validate
-
-## Progress Log
-
-- **2025-10-08**: Initial plan created based on codebase analysis
-- **2025-10-08**: Completed step 1 - Added hover assertion type to assertion.rs
-  - Added `Hover` variant to `UnparsedAssertion` and `ParsedAssertion` enums
-  - Created `HoverAssertion` struct and `HoverAssertionParseError` enum
-  - Updated `from_comment()` to recognize `# hover:` and `# ↓ hover:` patterns
-  - Simplified approach: down arrow must appear immediately before `hover` keyword
-  - Added placeholder matching logic in matcher.rs (TODO: implement once diagnostics ready)
-  - ty_test compiles successfully with warnings (unused code, expected at this stage)
-- **2025-10-08**: Completed step 3 - Created CheckOutput enum infrastructure
-  - Decided NOT to add HoverType to DiagnosticId (keep test logic separate)
-  - Created `CheckOutput` enum with `Diagnostic` and `Hover` variants
-  - Implemented `SortedCheckOutputs` to handle sorting/grouping by line
-  - Updated entire matcher module to work with `CheckOutput` instead of `Diagnostic`
-  - Updated lib.rs to convert diagnostics to `CheckOutput` before matching
-  - All changes compile successfully
-- **2025-10-08**: Completed steps 4 & 5 - Implemented hover type inference and matching
-  - Avoided adding ty_ide dependency; used ty_python_semantic directly
-  - Implemented find_covering_node() using AST visitor pattern
-  - Implemented infer_type_at_position() using HasType trait on AST nodes
-  - Implemented generate_hover_outputs() to scan comments and generate hover results
-  - Integrated hover outputs into check flow
-  - Implemented hover matching logic comparing inferred vs expected types
-  - **All core functionality now complete and compiling!**
-- **2025-10-08**: Step 6 in progress - Added test files and refined implementation
-  - Created comprehensive hover.md mdtest file with edge cases
-  - Fixed infer_type_at_position to handle expression statements (StmtExpr nodes)
-  - Learned that arrow positioning must align exactly with target expression characters
-- **2025-10-08**: Refactored to use ty_ide's existing infrastructure
-  - User feedback: original suggestion to avoid ty_ide dependency was a mistake
-  - Made ty_test::Db implement ty_project::Db (added project field)
-  - Added ty_project dependency to ty_test
-  - Made GotoTarget, find_goto_target, and GotoTarget::inferred_type public in ty_ide
-  - Exported GotoTarget, find_goto_target, Hover, and HoverContent from ty_ide
-  - Updated hover.rs to use ty_ide::find_goto_target instead of custom find_covering_node
-  - All tests pass with the refactored implementation
-  - **Implementation now uses ty_ide's existing covering node logic as requested**
-- **2025-10-08**: Completed step 6 - Added comprehensive unit tests
-  - Removed hover_simple.md (no longer needed, hover.md is comprehensive)
-  - Added 6 unit tests for hover assertion parsing in ty_test/src/assertion.rs:
-    - hover_basic: Basic hover assertion parsing
-    - hover_with_spaces_before_arrow: Arrow with leading whitespace
-    - hover_complex_type: Complex type with @Todo metadata
-    - hover_multiple_on_same_line: Multiple hover assertions on same target line
-    - hover_mixed_with_other_assertions: Hover mixed with error assertions
-    - hover_parsed_column: Verify column extraction from arrow position
-  - All 104 ty_test unit tests pass
-  - **All implementation steps now complete!**