Fix Windows Unit Tests - file/path separators

- Fix all Windows unit tests (fixes #402)
- Small number of unit tests skipped on Windows, marked with TODOs

Testing:
- Fake OS specific file and path separators
- Explicit setFakeOS methods, e.g. setFakeOSWindows()
- Default to using native OS rather than fakeOSName for most unit tests
- Small number of unit tests use fakeOSName
- ‘inTestMustFakeOS’ setting removed

build.gradle

@@ -48,7 +48,6 @@ test {
         // of just pointing to an HTML file.
         exceptionFormat = 'full'
     }
-    systemProperty 'inTestMustFakeOS', 'true'
 }
 
 pluginBundle {

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/CycleFinderTask.groovy

@@ -93,7 +93,7 @@ class CycleFinderTask extends DefaultTask {
 
     @TaskAction
     void cycleFinder() {
-        String cycleFinderExec = "${getJ2objcHome()}/cycle_finder"
+        String cycleFinderExec = getJ2objcHome() + Utils.fileSeparator() + 'cycle_finder'
         List<String> windowsOnlyArgs = new ArrayList<String>()
         if (Utils.isWindows()) {
             cycleFinderExec = 'java'
@@ -125,7 +125,7 @@ class CycleFinderTask extends DefaultTask {
         ])
         // TODO: comment explaining ${project.buildDir}/classes
         String classpathArg = Utils.joinedPathArg(classpathFiles) +
-                              File.pathSeparator + "${project.buildDir}/classes"
+                              Utils.pathSeparator() + "${project.buildDir}/classes"
 
         ByteArrayOutputStream stdout = new ByteArrayOutputStream()
         ByteArrayOutputStream stderr = new ByteArrayOutputStream()

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/PackLibrariesTask.groovy

@@ -72,7 +72,7 @@ class PackLibrariesTask extends DefaultTask {
                 args 'lipo'
 
                 args '-create'
-                args '-output', "${outputLibDirFile}/lib${project.name}-j2objc.a"
+                args '-output', project.file("${outputLibDirFile}/lib${project.name}-j2objc.a").absolutePath
 
                 getLibrariesFiles().each { File libFile ->
                     args libFile.absolutePath

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/TestTask.groovy

@@ -222,25 +222,23 @@ class TestTask extends DefaultTask {
         }
     }
 
-    // Generate Test Names
-    // Generate list of tests from the source java files
-    // e.g. src/test/java/com/example/dir/ClassTest.java => "com.example.dir.ClassTest"
+    // Generate list of test names from the source java files
     // depends on --prefixes dir/prefixes.properties in translateArgs
+    //   Before:  src/test/java/com/example/dir/SomeTest.java
+    //   After:   com.example.dir.SomeTest or PREFIXSomeTest
     static List<String> getTestNames(Project proj, FileCollection srcFiles, Properties packagePrefixes) {
 
         List<String> testNames = srcFiles.collect { File file ->
-            // Overall goal is to take the File path to the test name:
-            // src/test/java/com/example/dir/SomeTest.java => com.example.dir.SomeTest
-            // Comments show the value of the LHS variable after assignment
-
-            String testName = proj.relativePath(file)  // com.example.dir.SomeTest
-                    .replace('src/test/java/', '')
-                    .replace('/', '.')
-                    .replace('.java', '')
+            // Comments indicate the value at the end of that statement
+            String testName = proj.relativePath(file)  // src/test/java/com/example/dir/SomeTest.java
+                            .replace('\\', '/')  // Windows backslashes converted to forward slash
+                            .replace('src/test/java/', '')  // com/example/dir/SomeTest.java
+                            .replace('.java', '')  // com/example/dir/SomeTest
+                            .replace('/', '.')  // com.example.dir.SomeTest
 
             // Translate test name according to prefixes.properties
-            // Prefix Property: com.example.dir: Prefix
-            // Test Name: com.example.dir.SomeTest => PrefixSomeTest
+            // Prefix Property: com.example.dir: PREFIX
+            // Test Name: com.example.dir.SomeTest => PREFIXSomeTest
 
             // First match against the set of Java packages, excluding the filename
             Matcher matcher = (testName =~ /^(([^.]+\.)+)[^.]+$/)  // (com.example.dir.)SomeTest
@@ -249,10 +247,10 @@ class TestTask extends DefaultTask {
                 String namespaceChopped = namespace[0..-2]  // com.example.dir
                 if (packagePrefixes.containsKey(namespaceChopped)) {
                     String prefix = packagePrefixes.getProperty(namespaceChopped)
-                    testName = testName.replace(namespace, prefix)  // PrefixSomeTest
+                    testName = testName.replace(namespace, prefix)  // PREFIXSomeTest
                 }
             }
-            return testName  // com.example.dir.SomeTest or PrefixSomeTest
+            return testName  // com.example.dir.SomeTest or PREFIXSomeTest
         }
         return testNames
     }

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/TranslateTask.groovy

@@ -235,7 +235,7 @@ class TranslateTask extends DefaultTask {
         ])
         // TODO: comment explaining ${project.buildDir}/classes
         String classpathArg = Utils.joinedPathArg(classpathFiles) +
-                              File.pathSeparator + "${project.buildDir}/classes"
+                              Utils.pathSeparator() + "${project.buildDir}/classes"
 
         ByteArrayOutputStream stdout = new ByteArrayOutputStream()
         ByteArrayOutputStream stderr = new ByteArrayOutputStream()

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/Utils.groovy

@@ -60,37 +60,73 @@ class Utils {
         }
     }
 
+    private static String fakeOSName = ''
+
+    // This allows faking of is(Linux|Windows|MacOSX) methods but misses java.io.File separators
+    // One of the following four methods should be called in @Before method to isolate test state
+    @VisibleForTesting
+    static void setFakeOSLinux() {
+        fakeOSName = 'Linux'
+    }
+
+    @VisibleForTesting
+    static void setFakeOSMacOSX() {
+        fakeOSName = 'Mac OS X'
+    }
+
     @VisibleForTesting
-    static String fakeOSName = ''
+    static void setFakeOSWindows() {
+        fakeOSName = 'Windows'
+    }
 
+    // Unset fake os, should be needed for @Before method
     @VisibleForTesting
-    static String getLowerCaseOSName() {
+    static void setFakeOSNone() {
+        fakeOSName = ''
+    }
+
+    @VisibleForTesting
+    static String getLowerCaseOSName(boolean ignoreFakeOSName) {
 
         String osName = System.getProperty('os.name')
-        if (!fakeOSName.isEmpty()) {
-            osName = fakeOSName
-        } else {
-            if (System.getProperty('inTestMustFakeOS') == 'true') {
-                throw new InvalidUserDataException(
-                        "Tests must set Utils.fakeOSName = 'OS NAME'\n" +
-                        "This ensure that tests don't depend on the system environment")
+        if (!ignoreFakeOSName) {
+            if (!fakeOSName.isEmpty()) {
+                osName = fakeOSName
             }
         }
         osName = osName.toLowerCase()
         return osName
     }
 
-    static boolean isWindows() {
-        String osName = getLowerCaseOSName()
-        return osName.contains('windows')
+    static boolean isLinux() {
+        String osName = getLowerCaseOSName(false)
+        // http://stackoverflow.com/a/18417382/1509221
+        return osName.contains('nux')
     }
 
     static boolean isMacOSX() {
-        String osName = getLowerCaseOSName()
-        // From: http://stackoverflow.com/a/18417382/1509221
+        String osName = getLowerCaseOSName(false)
+        // http://stackoverflow.com/a/18417382/1509221
         return osName.contains('mac') || osName.contains('darwin')
     }
 
+    static boolean isWindows() {
+        String osName = getLowerCaseOSName(false)
+        return osName.contains('windows')
+    }
+
+    static boolean isWindowsNoFake() {
+        String osName = getLowerCaseOSName(true)
+        return osName.contains('windows')
+    }
+
+    @VisibleForTesting
+    static final String windowsAbsolutePathPrefix = 'C:'
+
+    static boolean isWindowsNoFakeAbsolutePath(String path) {
+        return isWindowsNoFake() && path.startsWith(windowsAbsolutePathPrefix)
+    }
+
     static void requireMacOSX(String taskName) {
         if (!isMacOSX()) {
             throw new InvalidUserDataException(
@@ -99,6 +135,29 @@ class Utils {
         }
     }
 
+    // Same as File.separator but can mocked using fakeOSName
+    static String fileSeparator() {
+        if (isWindows()) {
+            return '\\'
+        } else {
+            return '/'
+        }
+    }
+
+    // Same as File.pathSeparator but can mocked using fakeOSName
+    static String pathSeparator() {
+        if (isWindows()) {
+            return ';'
+        } else {
+            return ':'
+        }
+    }
+
+    static String osTestCompatPath(String path) {
+        // Replace the native OS separator char with the possibly faked separator
+        return path.replace(File.separator, fileSeparator()).replace('/', fileSeparator())
+    }
+
     static void throwIfNoJavaPlugin(Project proj) {
         if (!proj.plugins.hasPlugin('java')) {
             String message =
@@ -172,8 +231,8 @@ class Utils {
     // MUST be used only in @Input getJ2objcHome() methods to ensure up-to-date checks are correct
     // @Input getJ2objcHome() method can be used freely inside the task action
     static String j2objcHome(Project proj) {
-        String result = getLocalProperty(proj, 'home')
-        if (result == null) {
+        String j2objcHome = getLocalProperty(proj, 'home')
+        if (j2objcHome == null) {
             String message =
                     "J2ObjC Home not set, this should be configured either:\n" +
                     "1) in a 'local.properties' file in the project root directory as:\n" +
@@ -186,15 +245,13 @@ class Utils {
                     "https://github.com/google/j2objc/releases"
             throw new InvalidUserDataException(message)
         }
-        if (!proj.file(result).exists()) {
-            String message = "J2OjcC Home directory not found, expected location: ${result}"
+        File j2objcHomeFile = new File(j2objcHome)
+        if (!j2objcHomeFile.exists()) {
+            String message = "J2OjcC Home directory not found, expected location: ${j2objcHome}"
             throw new InvalidUserDataException(message)
         }
-        // Trailing slashes cause problems with string concatenation logic.
-        if (result != null && result.endsWith('/')) {
-            result = result.substring(0, result.length() - 1)
-        }
-        return result
+        // File removes trailing slashes cause problems with string concatenation logic
+        return j2objcHomeFile.absolutePath
     }
 
     // Reads properties file and arguments from translateArgs (last argument takes precedence)
@@ -297,7 +354,7 @@ class Utils {
             paths += file.path
         }
         // OS specific separator, i.e. ":" on OS X and ";" on Windows
-        return paths.join(File.pathSeparator)
+        return paths.join(pathSeparator())
     }
 
     static String trimTrailingForwardSlash(String path) {

src/main/groovy/com/github/j2objccontrib/j2objcgradle/tasks/XcodeTask.groovy

@@ -148,7 +148,7 @@ class XcodeTask extends DefaultTask {
             try {
                 logger.debug('XcodeTask - projectExec - pod install:')
                 Utils.projectExec(project, stdout, stderr, null, {
-                    setWorkingDir getXcodeProjectDir()
+                    setWorkingDir project.file(getXcodeProjectDir())
                     executable 'pod'
                     args 'install'
                     setStandardOutput stdout
@@ -208,10 +208,12 @@ class XcodeTask extends DefaultTask {
         if (path.endsWith('/')) {
             throw new InvalidUserDataException("Path shouldn't end with '/': $path")
         }
-        if (relative && path.startsWith('/')) {
+        // This allows the unit tests to run on Windows using their absolute paths
+        boolean relativePath = path.startsWith('/') || Utils.isWindowsNoFakeAbsolutePath(path)
+        if (relative && relativePath) {
             throw new InvalidUserDataException("Path shouldn't be absolute: $path")
         }
-        if (!relative && !path.startsWith('/')) {
+        if (!relative && !relativePath) {
             throw new InvalidUserDataException("Path shouldn't be relative: $path")
         }
         if (path.endsWith('*')) {