Ease debugging, fix some CI issues, tweak folder structure (#200)

* Enable debug for OTP versions' listings

* Make it easier to detect

* Prevent error annotation on expected error

The fact that one mirror fails in the above test and others follow
working is test enough for me

A single failing mirror should fail, but it's confusing to have
an error annotation for a success (via continue-on-error) while
not being able to suppress it via GitHub Actions

* Trying to figure out why we have a rebar_core exception

Might simply be that the bug is already fixed and we need to bump rebar3

* Try to debug into non-JSON input

* Prevent error in rebar_core

We're getting Access Denied for
Fetching registry from "https://repo.hex.pm:443/registry.ets.gz?"

* Try to figure out what's breaking tests

* Make jsonParse(...).map failure more understandable

* Ease test maintenance

* Tweak folder structure while moving console._ to core._

test/problem-matchers.test.js

@@ -0,0 +1,82 @@
+const assert = require('assert')
+const core = require('@actions/core')
+const { problemMatcher } = require('../matchers/elixir-matchers.json')
+
+async function all() {
+  await testElixirMixCompileError()
+  await testElixirMixCompileWarning()
+  await testElixirMixTestFailure()
+  await testElixirCredoOutputDefault()
+}
+
+async function testElixirMixCompileError() {
+  const [matcher] = problemMatcher.find(
+    ({ owner }) => owner === 'elixir-mixCompileError',
+  ).pattern
+
+  const output = '** (CompileError) lib/test.ex:16: undefined function err/0'
+  const [message, , file, line] = output.match(matcher.regexp)
+  assert.equal(file, 'lib/test.ex')
+  assert.equal(line, '16')
+  assert.equal(message, output)
+}
+
+async function testElixirMixCompileWarning() {
+  const [messagePattern, filePattern] = problemMatcher.find(
+    ({ owner }) => owner === 'elixir-mixCompileWarning',
+  ).pattern
+
+  const firstOutput =
+    'warning: variable "err" does not exist and is being expanded to "err()"'
+  const secondOutput = '  lib/test.ex:16: Test.hello/0'
+
+  const [, message] = firstOutput.match(messagePattern.regexp)
+  assert.equal(
+    message,
+    'variable "err" does not exist and is being expanded to "err()"',
+  )
+
+  const [, file, line] = secondOutput.match(filePattern.regexp)
+  assert.equal(file, 'lib/test.ex')
+  assert.equal(line, '16')
+}
+
+async function testElixirMixTestFailure() {
+  const [messagePattern, filePattern] = problemMatcher.find(
+    ({ owner }) => owner === 'elixir-mixTestFailure',
+  ).pattern
+
+  const firstOutput = '1) test throws (TestTest)'
+  const secondOutput = '  test/test_test.exs:9'
+
+  const [, message] = firstOutput.match(messagePattern.regexp)
+  assert.equal(message, 'test throws (TestTest)')
+
+  const [, file, line] = secondOutput.match(filePattern.regexp)
+  assert.equal(file, 'test/test_test.exs')
+  assert.equal(line, '9')
+}
+
+async function testElixirCredoOutputDefault() {
+  const [messagePattern, filePattern] = problemMatcher.find(
+    ({ owner }) => owner === 'elixir-credoOutputDefault',
+  ).pattern
+
+  const firstOutput = '┃ [F] → Function is too complex (CC is 29, max is 9).'
+  const secondOutput = '┃       lib/test.ex:15:7 #(Test.hello)'
+
+  const [, message] = firstOutput.match(messagePattern.regexp)
+  assert.equal(message, 'Function is too complex (CC is 29, max is 9).')
+
+  const [, file, line, column] = secondOutput.match(filePattern.regexp)
+  assert.equal(file, 'lib/test.ex')
+  assert.equal(line, '15')
+  assert.equal(column, '7')
+}
+
+all()
+  .then(() => process.exit(0))
+  .catch((err) => {
+    core.error(err)
+    process.exit(1)
+  })