Introduce rebar-version (#9)

Previously (Remove redundant code) (+27 squashed commits)
Squashed commits:
[0b79c31] Rename as setup-beam
[312b42b] Simplify platform verification
[b43ca96] Prevent use of OTP- prefixed Erlang/OTP versions
[103a236] Move the promise-based approach to an async-based approach

(not testing for failure, so not guaranteeing readable/usable output either)
[1e7f631] Remove local test files
[d03e0c6] Prevent use of -otp- infixed Elixir versions
[697110e] Have versions output in action, not just in tests
[7360781] Ease test validations
[71e6999] Reinstall tests that were there before
[6602f20] Attempt at simplifying regexp matching with build listings
[09247af] Provide for an Elixir to "not OTP" fallback mechanism

(as explained by the comments)
[dfc4083] Attempt at renaming for clarity

We also get rid of return values when not reachable
We also move the `-otp-` part of the Elixir version upstream so it's easy to reason about
  (and update the tests accordingly)
[0d4eb28] Bump our dep.s

(trying to figure out why core.setFailed isn't making the action fail, as it should)
[ebf48ef] Have action fail (with an exception) when no expected version is found

(we otherwise feel that a simple warning is not enough, as it may end up hiding potential bugs)
[8478364] Adapt tests to our actual inputs
[16ea63d] Add prettier again, now sync'ed with jslint

(pass it on the code, already)
[cfc65df] Improve error messages and tests
[a017948] Test unavailable Elixir upon mix
[7f2a3e9] Test failing installations

Also output core.error when expected
[08061ca] Attempt at making shell scripts more robust
[4ee73cb] Separate test code from production code

1. inputs (for CI) are managed by code, not by .yml env. variables
2. rebar3_builds.txt added for stable repeatability
3. tests tweaked to make it easier to modify and drop dependency on production code
4. `dist` regenerated (duplicate files gone)
5. setup-elixir.js tweaked to this new reality
[d17fed4] Remove prettier from the package
[7d6f8f5] Actually break CI when we should
[b972eaf] Remove unrequired element
[0ffa28a] Ease maintenance and readability
[4690169] Fix as per broken tests
[a1371c6] Merge setup-erlang in

.eslintrc.yml

@@ -0,0 +1,16 @@
+---
+env:
+  node: true
+  es2021: true
+extends:
+  - google
+parserOptions:
+  ecmaVersion: 12
+rules: {
+  indent: ["warn", 2],
+  max-len: ["warn", 100],
+  no-unused-vars: ["error", {"varsIgnorePattern": "^_"}],
+  require-jsdoc: 0,
+  semi: 0,
+  no-undef: "error"
+}

.gitattributes

@@ -1,2 +1 @@
 node_modules/** -diff linguist-generated=true
-.licenses/** -diff linguist-generated=true

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+---
+name: ci
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  check_integrity:
+    name: Make sure expected pre-release actions are performed
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: '12'
+      - run: npm install -g npm
+      - run: npm install
+      - run: npm run format
+      - run: npm install -g markdownlint-cli
+      - run: npm run markdownlint
+      - run: npm run shellcheck
+      - run: npm run yamllint
+      - run: npm run jslint
+      - run: npm run licenses
+      - run: npm run build
+      - name: Check if build left artifacts
+        run: git diff --exit-code

.github/workflows/test.yml

@@ -1,4 +1,5 @@
-name: Test
+---
+name: test
 
 on:
   push: {branches: main}
@@ -8,8 +9,8 @@ on:
 
 jobs:
   unit_test:
+    name: Pre-release unit tests
     runs-on: ubuntu-latest
-    name: Unit tests
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
@@ -18,17 +19,26 @@ jobs:
       - run: npm test
 
   integration_test:
-    runs-on: ubuntu-latest
-    name: OTP ${{matrix.pair.otp-version}} / Elixir ${{matrix.pair.elixir-version}}
+    name: >
+      Pre-release integration tests
+      (Erlang/OTP ${{matrix.pair.otp-version}},
+       Elixir ${{matrix.pair.elixir-version}},
+       rebar3 ${{matrix.pair.rebar3-version}})
+    runs-on: ubuntu-18.04
     strategy:
+      fail-fast: false
       matrix:
         pair:
           # Full Versions
           - otp-version: '22.0'
             elixir-version: '1.9.1'
+          - otp-version: '22.3.4'
+            rebar3-version: '3.14.4'
           # Semver ranges
           - otp-version: '21.x'
             elixir-version: '<1.9.1'
+          - otp-version: '21.x'
+            rebar3-version: '3.14.4'
           # Branches
           - otp-version: '22.0'
             elixir-version: master
@@ -37,18 +47,73 @@ jobs:
           # Pre-releases
           - otp-version: '23.0'
             elixir-version: '1.11.0-rc.0'
+          # Fallback to Elixir (with no OTP)
+          - otp-version: '24.0-rc1'
+            elixir-version: '1.9.3'
+          # Miscellaneous combos
+          - elixir-version: 'master'
+            otp-version: '22.3'
+          - elixir-version: 'master'
+            otp-version: '22'
+          - elixir-version: 'master'
+            otp-version: '^22'
+          - elixir-version: 'master'
+            otp-version: '22'
+          - elixir-version: '1.6.5'
+            otp-version: 'maint-21'
+          - elixir-version: 'v1.6.5'
+            otp-version: 'maint-21'
+          - elixir-version: 'v1.9.x'
+            otp-version: '21.1'
+          - elixir-version: '1.9.x'
+            otp-version: '21'
+          - elixir-version: 'v1.8.x'
+            otp-version: '22'
+          - elixir-version: 'v1.8.x'
+            otp-version: '23.1'
+          - elixir-version: 'v1.8'
+            otp-version: '^22.3'
+          - elixir-version: 'v1.10'
+            otp-version: '21.x'
+          - elixir-version: 'v1.x'
+            otp-version: 'master'
+          - elixir-version: 'v1.11.0-rc.0'
+            otp-version: '23'
+          - elixir-version: 'v1.11.0-rc.0'
+            otp-version: '23.0'
+          - elixir-version: 'v1.11.0-rc.0'
+            otp-version: 'master'
     steps:
       - uses: actions/checkout@v2
-      - name: Use erlef/setup-elixir
-        id: setup-elixir
+      - name: Use erlef/setup-beam
+        id: setup-beam
         uses: ./
         with:
           otp-version: ${{matrix.pair.otp-version}}
           elixir-version: ${{matrix.pair.elixir-version}}
-      - name: Output runtime versions
-        run: echo "Elixir ${{steps.setup-elixir.outputs.elixir-version}} / OTP ${{steps.setup-elixir.outputs.otp-version}}"
+          rebar3-version: ${{matrix.pair.rebar3-version}}
+      - name: Erlang/OTP version (action)
+        run: echo "Erlang/OTP ${{steps.setup-beam.outputs.otp-version}}"
+      - name: Elixir version (action)
+        run: echo "Elixir ${{steps.setup-beam.outputs.elixir-version}}"
+        if: ${{matrix.pair.elixir-version}}
+      - name: rebar3 version (action)
+        run: echo "rebar3 ${{steps.setup-beam.outputs.rebar3-version}}"
+        if: ${{matrix.pair.rebar3-version}}
+      - name: mix version and help (CLI)
+        run: |
+          mix -v
+          mix help local.rebar
+          mix help local.hex
+        if: ${{matrix.pair.elixir-version}}
       - name: Run Mix project tests
-        run: |-
-          cd test-project
+        run: |
+          cd test-projects/mix
           mix deps.get
           mix test
+        if: ${{matrix.pair.elixir-version}}
+      - name: Run rebar3 project tests
+        run: |
+          cd test-projects/rebar3
+          rebar3 as test do xref,dialyzer,ct,cover
+        if: ${{matrix.pair.rebar3-version}}

.gitignore

@@ -0,0 +1 @@
+node_modules/**