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 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)
Speed	Fast (~10s)	Slow (full rebuild, ~1–2 min)
Coverage	Fixable analyzers only (CA*, S*, IDE*, IDISP*)	All Roslyn diagnostics: CS* + CA* + S* + IDE* + IDISP* + ASP* + MUD* + xUnit* etc.
CS* compiler warnings (CS8602, CS0618, …)	❌ skipped	✅ included
Editorconfig severity respected	✅	✅ (filters SARIF level=note/none and suppressions[])
NU* (NuGet vulnerabilities)	❌	❌ (restore phase, not in SARIF)
MSB* (MSBuild engine)	❌	❌ (build engine, not in SARIF)
Side effects	None	Forces full rebuild; writes per-project _analyzer-diag.sarif

When to use which

• Default (no flag) — quick triage of fixable issues; iterating on dotnet format fixes.
• --sarif — only when user explicitly asks for "everything", "full picture", "real warning count", or notices the default dashboard is undercounting compared to dotnet build. Never run unprompted: it triggers a full rebuild.

What it does

Default mode:

1. Runs dotnet format style --verify-no-changes --severity warn --report <tmpdir>
2. Runs dotnet format analyzers --verify-no-changes --severity warn --report <tmpdir>
3. Transforms format-report.json via jq into violation summaries and file-level details
4. Injects data into scripts/template.html, writes output HTML

--sarif mode:

1. Cleans prior _analyzer-diag.sarif files
2. Runs dotnet build <project> -t:Rebuild -p:ErrorLog=_analyzer-diag.sarif%2cversion=2.1
3. Globs all per-project SARIF, drops source-suppressed and level∉{warning,error} results, dedupes by (ruleId, uri, line, col) (collapses multi-target duplicates)
4. Routes IDE* into the style bucket, everything else into analyzer bucket, injects into template.html