Add end-to-end continuous integration tests for Homebrew distribution (#243)

* Add the possibility to test homebrew's swift-doc in the e2e tests.

* Add an GitHub action to make sure we don't break the homebrew version.

* Apply suggestions from code review

* Rename swiftDocCommand helper

Pass swiftDocCommand directly to Process.run

Co-authored-by: Mattt <mattt@me.com>

Author: Lukas-Stuehrk

.github/workflows/homebrew_ci.yml

@@ -0,0 +1,45 @@
+name: Homebrew CI
+
+on:
+  push:
+    branches: [master]
+  schedule:
+    - cron: 0 0 * * *
+
+jobs:
+  homebrew-bottle:
+    runs-on: macos-10.15
+    name: Test Homebrew installation from bottle
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - uses: actions/cache@v2
+        with:
+          path: .build
+          key: ${{ runner.os }}-spm-xcode-${{ matrix.xcode }}-${{ hashFiles('**/Package.resolved') }}
+          restore-keys: |
+            ${{ runner.os }}-spm-xcode-${{ matrix.xcode }}-
+      - name: Install swift-doc
+        run: brew install swiftdocorg/formulae/swift-doc --force-bottle
+      - name: Run Tests
+        run: |
+          swift test --filter EndToEndTests. -Xswiftc -DUSE_HOMEBREW
+
+  homebrew-sources:
+    runs-on: macos-11.0
+
+    name: Test Homebrew installation from sources
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - uses: actions/cache@v2
+        with:
+          path: .build
+          key: ${{ runner.os }}-spm-xcode-${{ hashFiles('**/Package.resolved') }}
+          restore-keys: |
+            ${{ runner.os }}-spm-xcode-
+      - name: Install swift-doc
+        run: brew install swiftdocorg/formulae/swift-doc --build-from-source
+      - name: Run Tests
+        run: swift test --filter EndToEndTests. -Xswiftc -DUSE_HOMEBREW

Tests/EndToEndTests/CoverageSubcommandTests.swift

@@ -2,12 +2,10 @@ import XCTest
 
 final class CoverageSubcommandTests: XCTestCase {
     func testStandardOutput() throws {
-        let command = Bundle.productsDirectory.appendingPathComponent("swift-doc")
-
         let outputDirectory = try temporaryDirectory()
         defer { try? FileManager.default.removeItem(at: outputDirectory) }
 
-        try Process.run(command: command,
+        try Process.run(command: swiftDocCommand,
                         arguments: [
                             "coverage",
                             "Sources"
@@ -20,13 +18,11 @@ final class CoverageSubcommandTests: XCTestCase {
     }
 
     func testFileOutput() throws {
-        let command = Bundle.productsDirectory.appendingPathComponent("swift-doc")
-        
         let outputDirectory = try temporaryDirectory()
         let outputFile = outputDirectory.appendingPathComponent("report.json")
         defer { try? FileManager.default.removeItem(at: outputDirectory) }
 
-        try Process.run(command: command,
+        try Process.run(command: swiftDocCommand,
                         arguments: [
                             "coverage",
                             "--output", outputFile.path,

Tests/EndToEndTests/DiagramSubcommandTests.swift

@@ -2,12 +2,10 @@ import XCTest
 
 final class DiagramSubcommandTests: XCTestCase {
     func testStandardOutput() throws {
-        let command = Bundle.productsDirectory.appendingPathComponent("swift-doc")
-
         let outputDirectory = try temporaryDirectory()
         defer { try? FileManager.default.removeItem(at: outputDirectory) }
 
-        try Process.run(command: command,
+        try Process.run(command: swiftDocCommand,
                         arguments: [
                             "diagram",
                             "Sources"

Tests/EndToEndTests/GenerateSubcommandTests.swift

@@ -2,12 +2,10 @@ import XCTest
 
 final class GenerateSubcommandTests: XCTestCase {
     func testCommonMark() throws {
-        let command = Bundle.productsDirectory.appendingPathComponent("swift-doc")
-
         let outputDirectory = try temporaryDirectory()
         defer { try? FileManager.default.removeItem(at: outputDirectory) }
 
-        try Process.run(command: command,
+        try Process.run(command: swiftDocCommand,
                         arguments: [
                             "generate",
                             "--module-name", "SwiftDoc",
@@ -44,11 +42,10 @@ final class GenerateSubcommandTests: XCTestCase {
     }
 
     func testHTML() throws {
-        let command = Bundle.productsDirectory.appendingPathComponent("swift-doc")
         let outputDirectory = try temporaryDirectory()
 
         defer { try? FileManager.default.removeItem(at: outputDirectory) }
-        try Process.run(command: command,
+        try Process.run(command: swiftDocCommand,
                         arguments: [
                             "generate",
                             "--module-name", "SwiftDoc",

Tests/EndToEndTests/Helpers/XCTestCase+Extensions.swift

@@ -0,0 +1,12 @@
+import XCTest
+import Foundation
+
+extension XCTestCase {
+    var swiftDocCommand: URL {
+        #if USE_HOMEBREW
+        return URL(fileURLWithPath: "/usr/local/bin/swift-doc")
+        #else
+        return Bundle.productsDirectory.appendingPathComponent("swift-doc")
+        #endif
+    }
+}