/dotnet-analyzers

name: dotnet-analyzers
description:   Run dotnet format to fix code style and analyzer diagnostics (IDE0005, CA*, SA*). Use when fixing unnecessary usings, code style violations, analyzer warnings, or verifying format compliance
argument-hint: "[diagnostic ID or 'verify' or 'list' or '--dashboard' or '--sarif']"
allowed-tools: Bash(dotnet format *), Bash(dotnet clean *), Bash(jq *), Bash(bash *generate-report*), Read, Grep, Glob

.NET Analyzers & Code Format

Fix code style and analyzer diagnostics using `dotnet format`.

Arguments: $ARGUMENTS

Key Concepts

• `dotnet format` does its own internal compilation — it does NOT depend on cached build output
• CA*/SA* rules (analyzers) run during build if `EnableNETAnalyzers` is true

Command Reference

| Task | Command | |------|---------| | Fix specific style diagnostic | `dotnet format style --diagnostics IDE0005 --severity warn` | | Fix specific analyzer diagnostic | `dotnet format analyzers --diagnostics CA1305 --severity warn` | | Fix all style issues | `dotnet format style --severity warn` | | Fix all analyzer issues | `dotnet format analyzers --severity warn` | | Fix everything | `dotnet format --severity warn` | | Verify only (CI) | `dotnet format --verify-no-changes --severity warn` | | List violations without fixing | `dotnet format style --verify-no-changes --severity warn -v diag` | | Scope to folder | `dotnet format style --diagnostics IDE0005 --include src/MyProject/` |

Common Diagnostics

Style (IDE*) — use `dotnet format style`

| ID | Description | |----|-------------| | IDE0005 | Unnecessary using directive | | IDE0055 | Fix formatting | | IDE0090 | Simplify `new` expression | | IDE0161 | File-scoped namespace | | IDE0251 | Make member readonly |

Analyzers (CA*) — use `dotnet format analyzers`

| ID | Description | |----|-------------| | CA1305 | Specify IFormatProvider | | CA1822 | Mark members as static | | CA1859 | Use concrete types for performance | | CA2000 | Dispose objects before losing scope |

Workflow

IMPORTANT: Always start in verify/list mode. NEVER auto-fix without explicit user confirmation.

Step 1: List violations (default)

Always start by showing what would change — never fix automatically. Use `--report "$TEMP/dotnet-format"` to get structured JSON, then process with `jq`.

# List all style violations as JSON report
dotnet format style --verify-no-changes --severity warn --report "$TEMP/dotnet-format" <PROJECT_OR_SOLUTION> 2>/dev/null

# List specific diagnostic
dotnet format style --verify-no-changes --diagnostics IDE0005 --severity warn --report "$TEMP/dotnet-format" <PROJECT_OR_SOLUTION> 2>/dev/null

# List analyzer violations
dotnet format analyzers --verify-no-changes --severity warn --report "$TEMP/dotnet-format" <PROJECT_OR_SOLUTION> 2>/dev/null

Process the JSON report with `jq`:

# Summary: count violations per diagnostic ID
jq '[.[].FileChanges[].DiagnosticId] | group_by(.) | map({id: .[0], count: length}) | sort_by(-.count)' "$TEMP/dotnet-format/format-report.json"

# List affected files
jq '[.[].FilePath] | unique | .[]' "$TEMP/dotnet-format/format-report.json"

# Show details for a specific diagnostic
jq '[.[] | {file: .FilePath, changes: [.FileChanges[] | select(.DiagnosticId == "IDE0005")]} | select(.changes | length > 0)]' "$TEMP/dotnet-format/format-report.json"

Step 2: Report findings to user

Summarize the violations found using the JSON report and ask the user if they want to apply fixes.

Step 3: Apply fixes (only after user confirms)

dotnet format style --diagnostics IDE0005 --severity warn

Or for analyzer rules:

dotnet format analyzers --diagnostics CA1305 --severity warn

Step 4: Verify build still passes

dotnet build -p:WarningLevel=0 /clp:ErrorsOnly

HTML Dashboard Report (`--dashboard`)

Only generate when user explicitly passes `--dashboard`. Do NOT suggest or run this unprompted.

`--sarif` selects SARIF mode: the script runs its own `dotnet build -t:Rebuild` and harvests `_analyzer-diag.sarif` files. It is NOT a request to run `dotnet build` separately — passing the flag through to `generate-report.sh` is the entire job. Without `--sarif`, the script uses the faster `dotnet format` path. SARIF mode respects editorconfig severity (filters `level=note`/`none` and source-suppressed entries). See [Mode comparison](#mode-comparison) for when to pick which.

Generate an interactive HTML dashboard from live `dotnet format` output. No AI involved — purely deterministic.

Usage

Default mode uses `dotnet format` (fast, fixable diagnostics only):

# From repo root (defaults to current dir, outputs analyzer-dashboard.html)
bash ~/.claude/skills/dotnet-analyzers/scripts/generate-report.sh

# Explicit solution/project path and output
bash ~/.claude/skills/dotnet-analyzers/scripts/generate-report.sh ./MyProject.sln analyzer-dashboard-generated.html

SARIF mode runs `dotnet build -t:Rebuild` and harvests Roslyn ErrorLog SARIF (slower, comprehensive):

# Run ONLY when user explicitly asks for full coverage / "report everything"
bash ~/.claude/skills/dotnet-analyzers/scripts/generate-report.sh --sarif presales.slnx analyzer-dashboard-sarif.html

Flag parsing: `--sarif` and `--dashboard` may appear in any order; `--dashboard` is a no-op (dashboard is always emitted) but accepted so user invocations like `--dashboard --sarif` work as expected. Positional args are `[project] [output.html]`.

When the user asks for **both** dashboards, generate them with distinct output names:

bash ~/.claude/skills/dotnet-analyzers/scripts/generate-report.sh presales.slnx analyzer-dashboard.html
bash ~/.claude/skills/dotnet-analyzers/scripts/generate-report.sh --sarif presales.slnx analyzer-dashboard-sarif.html

Mode comparison

| Aspect | default (`dotnet format`) | `--sarif` (Roslyn ErrorLog) | |--------|----------------------------|-------------------