Umbrella projects

An umbrella is not a single project with more files in it. Detection, findings, coverage and Sobelow all behave differently, and each difference exists because the naive behaviour was wrong in a way that looked like a pass.

Tool detection

An umbrella root's mix.exs usually declares no dependencies. Reading only the root reports credo, dialyzer and everything else as not installed, and a run that checks almost nothing passes.

ExQuality unions the root's dependencies with every child app's. A tool declared in one app enables its stage for the run.

Findings

Findings carry the app their file belongs to, and rendered output is grouped by app, so a finding is attributable without reading the path:

web
  lib/web/user_controller.ex
    42:3  [info] Modules should have a @moduledoc tag. (Credo.Check.Readability.ModuleDoc)

In the JSON report this is the finding's app field. See reports.md.

Tests

Test statistics are summed across every app, rather than the first app's numbers being reported as the whole suite's. A failure names the apps the failures came from:

✗ Tests: 3 of 4,180 failed (web: 3)

Coverage

A per-app mix test --cover only sees its own app's modules, so a module exercised by another app's tests reads as 0%.

With Elixir's built-in coverage, ExQuality runs mix test --cover --export-coverage default and then mix test.coverage to aggregate, which gives one table and one suite-wide total.

With excoveralls, every [TOTAL] line is read. When apps are measured separately, the lowest leads and the per-app numbers are reported alongside it.

Sobelow

mix sobelow at an umbrella root finds nothing to scan. ExQuality runs it once per child app that uses Phoenix, and tags each finding with the app it came from.

Configuration

.quality.exs is read from the project root. An umbrella child with no file of its own reads the umbrella root's.