# Implementation Plan: Rename Queries & Data Model Tables
**Branch**: `001-rename-queries-tables` | **Date**: 2025-12-19 | **Updated**: 2025-12-20 | **Spec**: spec.md
## Summary
Implement rename operations for existing Power Query queries.
For Data Model tables: expose the operation but return a clear error explaining the Excel limitation (table names are immutable).
Approach:
- Power Query: rename by setting the query object `Name` via Excel COM after trim + case-insensitive uniqueness checks.
- Data Model: attempt direct COM rename (will fail), return clear error explaining the limitation and workaround.
## Technical Context
**Language/Version**: C# / .NET 8
**Primary Dependencies**: Excel COM automation via `dynamic` + `ExcelMcp.ComInterop`, MCP SDK (`ModelContextProtocol`), `System.Text.Json`, CLI via `Spectre.Console.Cli`
**Storage**: Excel workbook files (`.xlsx`, `.xlsm`)
**Testing**: xUnit integration tests requiring installed Excel (Core/CLI/MCP server test projects)
**Target Platform**: Windows with desktop Excel installed
**Project Type**: Multi-project .NET solution (`Sbroenne.ExcelMcp.sln`)
**Performance Goals**: Typical rename operations complete within 10 seconds for normal workbooks (per spec SC-001)
**Constraints**: No auto-save, no interactive prompts; COM objects released in `finally`; Core exceptions propagate through batch layer
**Scale/Scope**: Single-workbook, single-operation commands; batch mode supported for multi-step workflows
## Constitution Check
*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*
PASS criteria for this feature:
- Result contract integrity: never return `Success=true` with `ErrorMessage`.
- MCP tools: return JSON for business failures; throw only for validation/preconditions.
- COM lifecycle: acquire COM objects in try; release in finally using `ComUtilities.Release(ref obj!)`.
- Core exception propagation: do not wrap `batch.Execute()` with catch/return patterns.
- Testing discipline: integration tests only; unique file per test; no `Save()` unless testing persistence.
- Coverage enforcement: new Core operations must be surfaced through MCP enums/switches.
## Project Structure
### Documentation (this feature)
```text
specs/001-rename-queries-tables/
├── plan.md # This file
├── research.md # Phase 0 output (verified 2025-12-20)
├── data-model.md # Phase 1 output
├── quickstart.md # Phase 1 output
├── contracts/ # Phase 1 output
└── tasks.md # Phase 2 output
```
### Source Code (repository root)
```text
src/
├── ExcelMcp.ComInterop/
├── ExcelMcp.Core/
├── ExcelMcp.McpServer/
└── ExcelMcp.CLI/
tests/
├── ExcelMcp.ComInterop.Tests/
├── ExcelMcp.Core.Tests/
├── ExcelMcp.McpServer.Tests/
└── ExcelMcp.CLI.Tests/
```
**Structure Decision**: Extend existing Core + MCP Server + CLI layers with new rename operations and integration tests.
## Complexity Tracking
No constitution violations anticipated.
## Phase 0: Research (Complete - VERIFIED)
Output: `research.md`
Key outcomes:
- Power Query rename: use Excel COM query object `Name` property (with repo-required validation semantics).
- **Data Model table rename: VERIFIED IMPOSSIBLE** via Excel COM API. `ModelTable.Name` is read-only and immutable.
## Phase 1: Design & Contracts (Complete)
Outputs:
- `data-model.md`: entities and validation rules.
- `contracts/rename-contracts.yaml`: conceptual request/response shapes for CLI/MCP.
- `quickstart.md`: CLI + MCP usage.
Post-design constitution check: still PASS (no new violations introduced by design).
## Phase 2: Implementation Plan
### Core (src/ExcelMcp.Core)
1) Add rename operations:
- Power Query: add `Rename(IExcelBatch batch, string oldName, string newName)` to `IPowerQueryCommands` + implement in `PowerQueryCommands`.
- Data Model: add `RenameTable(IExcelBatch batch, string oldName, string newName)` to `IDataModelCommands` + implement in `DataModelCommands`.
2) Validation behavior (both operations):
- Normalize by trimming input names.
- Reject empty/whitespace new names.
- No-op success when normalized names are equal.
- Uniqueness check is case-insensitive within the target scope, excluding the target being renamed.
- Case-only rename allowed: attempt COM rename.
3) COM implementation details:
- Acquire COM objects (e.g., `workbook.Queries`, query, model, model tables) in try block.
- Release every COM object in finally via `ComUtilities.Release(ref obj!)`.
- Do not wrap errors with Core-level catch blocks; let exceptions flow to batch layer.
4) Data Model rename strategy:
- Attempt direct rename first (will fail with `TargetParameterCountException`).
- Return clear error message explaining: "Data Model table names are immutable. Delete and recreate with new name."
- **NO fallback logic** - verified that no workaround exists.
### MCP Server (src/ExcelMcp.McpServer)
1) Add new actions to the relevant tool enums and switch routing:
- `excel_powerquery`: add `rename` action.
- `excel_datamodel`: add `rename-table` action.
2) Follow MCP result contract:
- Validation/precondition failures throw `McpException`.
- Business errors return serialized JSON result with `success: false`.
### CLI (src/ExcelMcp.CLI)
1) Power Query CLI:
- Add `rename` action to `PowerQueryCommand`.
- Add settings `--query` (old) and `--new-name` (new).
- Output JSON result.
2) Data Model CLI:
- Add `rename-table` action to `DataModelCommand`.
- Add settings `--table` (old) and `--new-name` (new).
### Tests (tests/*)
Add integration tests (feature-scoped):
PowerQuery:
- Rename existing query succeeds.
- Rename conflicts are rejected (case-insensitive + trim).
- Rename missing query fails.
- Trim-equal rename is no-op success.
- Case-only rename attempts COM rename (assert final list contains new casing).
DataModel:
- Attempt rename returns clear error about immutable table names.
- Conflict detection for model table rename (checked before COM attempt).
- Missing table returns "not found" error.
### Documentation & Guidance
- Update tool descriptions (XML summaries) for `excel_powerquery` and `excel_datamodel` to include rename semantics and constraints.
- Add/update MCP prompt guidance markdown to document the Data Model limitation.
