Dialyzer Integration

Integrating Dialyzer into development workflow and CI/CD pipelines.

Local Development

Initial Setup

Install dialyxir

mix deps.get

Build initial PLT (takes time first run)

mix dialyzer --plt

Run analysis

mix dialyzer

Incremental Analysis

Only analyze changed files

mix dialyzer --incremental

Force rebuild PLT

mix dialyzer --clean

CI/CD Integration

GitHub Actions

name: Dialyzer user-invocable: false

on: [push, pull_request]

jobs: dialyzer: runs-on: ubuntu-latest

steps:
  - uses: actions/checkout@v3

  - name: Set up Elixir
    uses: erlef/setup-beam@v1
    with:
      elixir-version: '1.15'
      otp-version: '26'

  - name: Restore dependencies cache
    uses: actions/cache@v3
    with:
      path: deps
      key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}

  - name: Restore PLT cache
    uses: actions/cache@v3
    id: plt-cache
    with:
      path: priv/plts
      key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}

  - name: Install dependencies
    run: mix deps.get

  - name: Create PLTs
    if: steps.plt-cache.outputs.cache-hit != 'true'
    run: mix dialyzer --plt

  - name: Run Dialyzer
    run: mix dialyzer --format github

GitLab CI

dialyzer: stage: test script: - mix local.hex --force - mix local.rebar --force - mix deps.get - mix dialyzer cache: paths: - _build/ - deps/ - priv/plts/

IDE Integration

VS Code (ElixirLS)

{ "elixirLS.dialyzerEnabled": true, "elixirLS.dialyzerFormat": "dialyxir_long", "elixirLS.dialyzerWarnOpts": [ "error_handling", "underspecs", "unmatched_returns" ] }

Vim/Neovim (coc-elixir)

{ "elixir.dialyzer.enabled": true }

Pre-commit Hooks

Using Husky/Lefthook

lefthook.yml

pre-commit: commands: dialyzer: glob: "*.ex" run: mix dialyzer --incremental

Git Hook Script

#!/bin/sh

.git/hooks/pre-commit

echo "Running Dialyzer..." mix dialyzer --incremental --quiet

if [ $? -ne 0 ]; then echo "Dialyzer found issues. Commit aborted." exit 1 fi

Team Workflow

Shared PLT Strategy

mix.exs

def project do [ dialyzer: [ plt_core_path: "priv/plts", plt_local_path: "priv/plts", plt_add_apps: [:mix, :ex_unit], # Shared across team via git plt_file: {:no_warn, "priv/plts/project.plt"} ] ] end

Baseline Approach

Generate baseline

mix dialyzer > dialyzer_baseline.txt

Check for new warnings

mix dialyzer | diff - dialyzer_baseline.txt

Performance Optimization

Parallel Analysis

def project do [ dialyzer: [ flags: [:error_handling], # Use multiple cores plt_add_deps: :app_tree ] ] end

Selective Analysis

Only check specific paths

mix dialyzer lib/critical/ test/important_test.exs

Incremental Mode

Much faster after initial run

mix dialyzer --incremental

Monitoring and Reporting

Custom Formatter

lib/custom_dialyzer_formatter.ex

defmodule CustomDialyzerFormatter do def format(warnings) do warnings |> Enum.map(&format_warning/1) |> Enum.join("\n") end

defp format_warning(warning) do # Custom formatting logic end end

Metrics Collection

Count warnings over time

mix dialyzer | grep -c "warning:" >> dialyzer_metrics.log

Troubleshooting

PLT Issues

Remove and rebuild

rm -rf _build/dev/.plt priv/plts/.plt mix dialyzer --plt

Memory Issues

Increase VM memory

elixir --erl "+hms 4096" -S mix dialyzer

Slow Analysis

Use incremental mode

mix dialyzer --incremental

Or analyze subset

mix dialyzer lib/core/