Elixir Collector

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Analyze Elixir/Mix projects to collect project metadata, Hex dependencies, CI/CD command tracking, and test coverage. Detects Phoenix, LiveView, and Ecto frameworks, and handles umbrella projects by walking `apps/*/mix.exs`.

Add elixir to your lunar-config.yml:

uses: github://earthly/lunar-lib/collectors/elixir@v1.0.5

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What This Integration Collects

This integration includes 4 collectors that gather metadata from your systems.

Collector code

`project`

Analyzes Elixir project structure by detecting mix.exs, mix.lock, .credo.exs, .formatter.exs, dialyzer config, and test directory. Parses project name/version, Elixir version requirement, OTP apps, umbrella members, and framework usage (Phoenix, LiveView, Ecto). Writes project metadata to .lang.elixir.

elixir mix mix.exs phoenix liveview ecto umbrella otp

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Collector code

`dependencies`

Extracts direct dependencies from mix.exs and resolved transitive versions from mix.lock when present. Captures Hex package name and version for each dependency. Writes dependency data to .lang.elixir.dependencies.

elixir dependencies hex mix.lock supply chain packages

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Collector ci-before-command

`cicd`

Records every mix command executed in CI pipelines along with the Elixir runtime version. Writes command strings and version info to .lang.elixir.cicd for audit trails and build reproducibility analysis.

elixir ci mix ci ci commands build tracking

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Collector ci-after-command

`test-coverage`

Extracts coverage percentage from excoveralls or mix test --cover output after tests complete. Parses coverage reports and writes results to .lang.elixir.tests.coverage.

excoveralls mix test test coverage coverage metrics

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How Collectors Fit into Lunar

Lunar watches your code and CI/CD systems to collect SDLC data from config files, test results, IaC, deployment configurations, security scans, and more.

Collectors are the automatic data-gathering layer. They extract structured metadata from your repositories and pipelines, feeding it into Lunar's centralized database where guardrails evaluate it to enforce your engineering standards.

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↓ Collectors Gather Data This Integration

Triggered by code changes or CI pipelines, collectors extract metadata from config files, tool outputs, test results, and scans

{ } Centralized as JSON

All data merged into each component's unified metadata document

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Example Collected Data

This collector writes structured metadata to the Component JSON. Here's an example of the data it produces:

{ } component.json Component JSON

{
  "lang": {
    "elixir": {
      "version": "1.16.2",
      "otp_version": "26",
      "build_systems": ["mix"],
      "mix_exs_exists": true,
      "mix_lock_exists": true,
      "project_name": "my_app",
      "project_version": "0.1.0",
      "elixir_requirement": "~> 1.15",
      "otp_apps": ["my_app"],
      "test_directory_exists": true,
      "credo_configured": true,
      "dialyzer_configured": true,
      "formatter_configured": true,
      "frameworks": ["phoenix", "phoenix_live_view", "ecto"],
      "umbrella": {
        "is_umbrella": true,
        "apps": ["my_app_web", "my_app_core"]
      },
      "source": { "tool": "mix", "integration": "code" },
      "cicd": {
        "cmds": [
          { "cmd": "mix test --cover", "version": "1.16.2" },
          { "cmd": "mix deps.get", "version": "1.16.2" }
        ]
      },
      "tests": {
        "coverage": {
          "percentage": 85.0,
          "source": { "tool": "excoveralls", "integration": "ci" }
        }
      },
      "dependencies": {
        "direct": [
          { "path": "phoenix", "version": "~> 1.7" },
          { "path": "phoenix_live_view", "version": "~> 0.20" },
          { "path": "ecto_sql", "version": "~> 3.10" }
        ],
        "transitive": [
          { "path": "telemetry", "version": "1.2.1" }
        ],
        "source": { "tool": "hex", "integration": "code" }
      }
    }
  },
  "testing": {
    "coverage": {
      "percentage": 85.0,
      "source": { "tool": "excoveralls", "integration": "ci" }
    }
  }
}

Documentation

View on GitHub

Elixir Collector

Collects Elixir/Mix project information, dependencies, CI/CD commands, and test coverage.

Overview

This collector gathers metadata about Elixir projects including mix project name/version, Elixir version requirement, OTP applications, Hex dependencies, umbrella app layout, and framework detection (Phoenix, LiveView, Ecto). It runs on both code changes (for static analysis) and CI hooks (to capture runtime metrics like test coverage and mix command usage).

Note: The CI-hook collectors (test-coverage, cicd) don't run tests — they observe and collect data from mix test / mix coveralls commands that your CI pipeline already runs.

Collected Data

This collector writes to the following Component JSON paths:

Path	Type	Description
`.lang.elixir`	object	Elixir project metadata
`.lang.elixir.version`	string	Elixir runtime version
`.lang.elixir.otp_version`	string	Erlang/OTP version
`.lang.elixir.build_systems`	array	Build systems detected (e.g., `["mix"]`)
`.lang.elixir.mix_exs_exists`	boolean	`mix.exs` detected
`.lang.elixir.mix_lock_exists`	boolean	`mix.lock` detected
`.lang.elixir.project_name`	string	Mix project name (from `project/0`)
`.lang.elixir.project_version`	string	Mix project version
`.lang.elixir.elixir_requirement`	string	Elixir version requirement (e.g. `"~> 1.15"`)
`.lang.elixir.otp_apps`	array	OTP application names (from `application/0`)
`.lang.elixir.test_directory_exists`	boolean	`test/` directory detected
`.lang.elixir.credo_configured`	boolean	`.credo.exs` detected
`.lang.elixir.dialyzer_configured`	boolean	Dialyzer configured via `:dialyxir` dep or `dialyzer/0` block in mix.exs (file-based signals only). The bundled `credo-or-dialyzer-configured` policy additionally OR's in `mix dialyzer` invocations from `.lang.elixir.cicd.cmds` — custom policies reading this field directly should consult `cicd.cmds` separately.
`.lang.elixir.formatter_configured`	boolean	`.formatter.exs` detected
`.lang.elixir.frameworks`	array	Frameworks detected from deps (e.g. `["phoenix", "phoenix_live_view", "ecto"]`)
`.lang.elixir.umbrella.is_umbrella`	boolean	Umbrella project flag
`.lang.elixir.umbrella.apps`	array	Umbrella member app names (from `apps/*/mix.exs`)
`.lang.elixir.cicd`	object	CI/CD command tracking with Elixir version
`.lang.elixir.tests`	object	Test coverage information
`.lang.elixir.dependencies`	object	Direct and transitive Hex dependencies
`.testing.coverage`	object	Normalized cross-language test coverage

Note: When a project is detected, .lang.elixir is always created (with at minimum source metadata), so policies can use its existence as a signal the component is an Elixir project.

Collectors

This plugin provides the following collectors (use include to select a subset):

Collector	Hook Type	Description
`project`	code	Collects project structure, versions, umbrella info, framework flags
`dependencies`	code	Collects Hex dependencies from mix.exs and mix.lock
`cicd`	ci-before-command	Tracks mix commands run in CI with Elixir version
`test-coverage`	ci-after-command	Extracts coverage from excoveralls or `mix test --cover`

Installation

Add to your lunar-config.yml:

collectors:
  - uses: github://earthly/lunar-lib/collectors/elixir@main
    on: ["domain:your-domain"]  # replace with your own domain or tags
    # include: [project, dependencies]  # Only include specific subcollectors

Open Source

This collector is open source and available on GitHub. Contribute improvements, report issues, or fork it for your own use.

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Common Use Cases

Explore guardrails that use data from Elixir Collector.

Mix Project Exists + Elixir Collector Ensures the project has a mix.exs file. Required for all Elixir projects managed...

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Elixir Version Constraint Set + Elixir Collector Ensures the project declares an Elixir version requirement (e.g., `elixir: "~>...

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Dependencies Locked + Elixir Collector Ensures mix.lock is committed for reproducible dependency resolution. Without a...

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Test Directory Exists + Elixir Collector Ensures a `test/` directory exists. An explicit test dir is the conventional...

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Credo Or Dialyzer Configured + Elixir Collector Ensures Credo or Dialyzer is configured. Credo is detected via `.credo.exs`....

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Umbrella App Detected + Elixir Collector Reports whether the project is an umbrella application. Informational — passes...

→

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Elixir Collector

What This Integration Collects

project

dependencies

cicd

test-coverage

How Collectors Fit into Lunar

Example Collected Data

Related

Documentation

Elixir Collector

Overview

Collected Data

Collectors

Installation

Open Source

Common Use Cases

Ready to Automate Your Standards?

`project`

`dependencies`

`cicd`

`test-coverage`