Add Travis CI for linux testing! (#33)

* wip

* all tests

* work around for suffix

* Revert "work around for suffix"

This reverts commit 489d50a.

* import foundation

* Revert "Revert "work around for suffix""

This reverts commit 85ec24c.

* attachment stuff

* wip

* wip

* omg

* omgomg

* wip

* wip

* clean up

* clean up

* does this work

* pr feedback

* clean

* another linux note

.dockerignore

@@ -0,0 +1,5 @@
+.git/
+.build/
+!.build/checkouts/
+!.build/repositories/
+!.build/workspace-state.json

.swift-version

@@ -0,0 +1 @@
+4.0

.travis.yml

@@ -0,0 +1,14 @@
+os:
+  - linux
+  - osx
+env:
+language: generic
+sudo: required
+dist: trusty
+osx_image: xcode9.1
+install:
+  - if [ $TRAVIS_OS_NAME = linux ]; then
+      eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)";
+    fi
+script:
+  - swift test

Dockerfile

@@ -0,0 +1,9 @@
+FROM swift:4.0
+
+WORKDIR /package
+
+COPY . ./
+
+RUN swift package resolve
+RUN swift package clean
+CMD swift test --parallel

Makefile

@@ -0,0 +1,2 @@
+test:
+	docker build --tag snapshot-testing . && docker run --rm snapshot-testing

README.md

@@ -1,4 +1,6 @@
-# swift-snapshot-testing [![CircleCI](https://circleci.com/gh/pointfreeco/swift-snapshot-testing.svg?style=svg)](https://circleci.com/gh/pointfreeco/swift-snapshot-testing)
+# swift-snapshot-testing
+
+macOS [![CircleCI](https://circleci.com/gh/pointfreeco/swift-snapshot-testing.svg?style=svg)](https://circleci.com/gh/pointfreeco/swift-snapshot-testing) Linux [![Build Status](https://travis-ci.org/pointfreeco/swift-snapshot-testing.svg?branch=master)](https://travis-ci.org/pointfreeco/swift-snapshot-testing)
 
 A library that records app data into test assertions. Because snapshot tests can capture the entirety of a data structure, they can cover far more surface area than a typical unit test.
 

Sources/Diff/Diff.swift

@@ -1,3 +1,5 @@
+import Foundation
+
 public enum DiffType {
   case first
   case second
@@ -83,8 +85,8 @@ public struct Hunk {
   }
 }
 
-public func chunk<S: StringProtocol>(diff diffs: [Diff<S>], context ctx: Int = 4) -> [Hunk] {
-  func prepending(_ prefix: String) -> (S) -> String {
+public func chunk(diff diffs: [Diff<String>], context ctx: Int = 4) -> [Hunk] {
+  func prepending(_ prefix: String) -> (String) -> String {
     return { prefix + $0 + ($0.hasSuffix(" ") ? "¬" : "") }
   }
   let changed: (Hunk) -> Bool = { $0.lines.contains(where: { $0.hasPrefix(minus) || $0.hasPrefix(plus) }) }
@@ -102,11 +104,11 @@ public func chunk<S: StringProtocol>(diff diffs: [Diff<S>], context ctx: Int = 4
           fstLen: ctx,
           sndIdx: current.sndIdx + current.sndLen + len - ctx,
           sndLen: ctx,
-          lines: (diff.elements.suffix(ctx) as ArraySlice<S>).map(prepending(figureSpace))
+          lines: (diff.elements.suffix(ctx) as ArraySlice<String>).map(prepending(figureSpace))
         )
         return (next, changed(hunk) ? hunks + [hunk] : hunks)
       case .both where current.lines.isEmpty:
-        let lines = (diff.elements.suffix(ctx) as ArraySlice<S>).map(prepending(figureSpace))
+        let lines = (diff.elements.suffix(ctx) as ArraySlice<String>).map(prepending(figureSpace))
         let count = lines.count
         return (current + Hunk(idx: len - count, len: count, lines: lines), hunks)
       case .both:

Sources/SnapshotTesting/Diffable.swift

@@ -2,6 +2,15 @@ import Diff
 import Foundation
 import XCTest
 
+#if os(Linux)
+  // NB: Linux doesn't have XCTAttachment, so stubbing out the minimal interface.
+  public struct XCTAttachment {}
+  extension XCTAttachment {
+    public init(string: String) {
+    }
+  }
+#endif
+
 public protocol Diffable {
   static var diffablePathExtension: String? { get }
   static func diffableDiff(_ fst: Self, _ snd: Self) -> (String, [XCTAttachment])?
@@ -39,8 +48,8 @@ extension String: Diffable {
     guard fst != snd else { return nil }
 
     let hunks = chunk(diff: diff(
-      fst.split(separator: "\n", omittingEmptySubsequences: false),
-      snd.split(separator: "\n", omittingEmptySubsequences: false)
+      fst.split(separator: "\n", omittingEmptySubsequences: false).map(String.init),
+      snd.split(separator: "\n", omittingEmptySubsequences: false).map(String.init)
     ))
     let failure = hunks.flatMap { [$0.patchMark] + $0.lines }.joined(separator: "\n")
 

Sources/SnapshotTesting/SnapshotTesting.swift

@@ -48,7 +48,7 @@ public func assertSnapshot<S: Snapshot>(
   }()
 
   let testName: String = {
-    let testIdentifier = "\(snapshotDirectoryUrl):\(function)"
+    let testIdentifier = "\(snapshotDirectoryUrl.absoluteString):\(function)"
     counter[testIdentifier, default: 0] += 1
     return "\(function.dropLast(2)).\(counter[testIdentifier]!)"
   }()
@@ -60,26 +60,32 @@ public func assertSnapshot<S: Snapshot>(
   try! fileManager.createDirectory(at: snapshotDirectoryUrl, withIntermediateDirectories: true)
 
   defer {
-    staleSnapshots[snapshotDirectoryUrl, default: Set(
-      try! fileManager.contentsOfDirectory(
-        at: snapshotDirectoryUrl, includingPropertiesForKeys: nil, options: .skipsHiddenFiles
-      )
-    )].remove(snapshotFileUrl)
-    _ = trackSnapshots
+    // NB: Linux doesn't have file manager enumeration capabilities, so we skip this work on Linux.
+    #if !os(Linux)
+      staleSnapshots[snapshotDirectoryUrl, default: Set(
+        try! fileManager.contentsOfDirectory(
+          at: snapshotDirectoryUrl, includingPropertiesForKeys: nil, options: .skipsHiddenFiles
+        )
+      )].remove(snapshotFileUrl)
+      _ = trackSnapshots
+    #endif
   }
-
+  
   let format = snapshot.snapshotFormat
   if !recording && fileManager.fileExists(atPath: snapshotFileUrl.path) {
     let reference = S.Format.fromDiffableData(try! Data(contentsOf: snapshotFileUrl))
     if let (failure, attachments) = S.Format.diffableDiff(reference, format) {
       XCTFail(failure, file: file, line: line)
       if !attachments.isEmpty {
-        XCTContext.runActivity(named: "Attached Failure Diff") { activity in
-          attachments.forEach {
-            $0.lifetime = .deleteOnSuccess
-            activity.add($0)
+        // NB: Linux doesn't have XCTAttachment, and we don't even need it, so can skip all of this work.
+        #if !os(Linux)
+          XCTContext.runActivity(named: "Attached Failure Diff") { activity in
+            attachments.forEach {
+              $0.lifetime = .deleteOnSuccess
+              activity.add($0)
+            }
           }
-        }
+        #endif
       }
     }
   } else {

Tests/LinuxMain.swift

@@ -0,0 +1,6 @@
+import XCTest
+@testable import SnapshotTestingTests
+
+XCTMain([
+    testCase(SnapshotTestingTests.allTests),
+])

Tests/SnapshotTestingTests/SnapshotTestingTests.swift

@@ -39,3 +39,15 @@ class SnapshotTestingTests: XCTestCase {
     assertSnapshot(matching: [1, 2])
   }
 }
+
+#if os(Linux)
+  extension SnapshotTestingTests {
+    static var allTests : [(String, (SnapshotTestingTests) -> () throws -> Void)] {
+      return [
+        ("testWithAny", testWithAny),
+        ("testWithNSObject", testWithNSObject),
+        ("testMultipleSnapshots", testMultipleSnapshots),
+      ]
+    }
+  }
+#endif