Move unsupported platform failure from os.name to separate method.

Previously we've accidentally depended on the isWindows check
to see if we're on a supported platform or not, this had
the unfortunate side-effect that even with `download = false`
we triggered the error(). See #178

Author: deepy

src/main/kotlin/com/github/gradle/node/task/NodeSetupTask.kt

@@ -49,11 +49,16 @@ abstract class NodeSetupTask : DefaultTask() {
 
     @TaskAction
     fun exec() {
+        failIfUnsupportedPlatform()
         deleteExistingNode()
         unpackNodeArchive()
         setExecutableFlag()
     }
 
+    private fun failIfUnsupportedPlatform() {
+        PlatformHelper.INSTANCE.failOnUnsupportedOs()
+    }
+
     private fun deleteExistingNode() {
         projectHelper.delete {
             delete(nodeDir.get().dir("../"))

src/main/kotlin/com/github/gradle/node/util/PlatformHelper.kt

@@ -9,9 +9,8 @@ open class PlatformHelper constructor(private val props: Properties = System.get
             name.contains("windows") -> "win"
             name.contains("mac") -> "darwin"
             name.contains("linux") -> "linux"
-            name.contains("freebsd") -> "linux"
             name.contains("sunos") -> "sunos"
-            else -> error("Unsupported OS: $name")
+            else -> "unsupported"
         }
     }
 
@@ -32,6 +31,14 @@ open class PlatformHelper constructor(private val props: Properties = System.get
 
     open val isWindows: Boolean by lazy { osName == "win" }
 
+    open val isSupported: Boolean by lazy { osName != "unsupported" }
+
+    fun failOnUnsupportedOs() {
+        if (!isSupported) {
+            error("Unsupported OS")
+        }
+    }
+
     private fun property(name: String): String {
         val value = props.getProperty(name)
         return value ?: System.getProperty(name) ?:
@@ -48,6 +55,11 @@ open class PlatformHelper constructor(private val props: Properties = System.get
 fun main(args: Array<String>) {
     println("Your os.name is: '${System.getProperty("os.name")}' and is parsed as: ${PlatformHelper.INSTANCE.osName}")
     println("Your os.arch is: '${System.getProperty("os.arch")}' and is parsed as: ${PlatformHelper.INSTANCE.osArch}")
+    if (!PlatformHelper.INSTANCE.isSupported) {
+        println("Your platform is \"unsupported\" (isSupported == false)")
+        println("Your platform does not support 'download = true' as there's no official Node.js binaries" +
+                " being published for it. You can still use the plugin, but you need to install Node.js manually")
+    }
     if (PlatformHelper.INSTANCE.isWindows) {
         println("You're on windows (isWindows == true)")
     } else {

src/test/groovy/com/github/gradle/node/util/PlatformHelperTest.groovy

@@ -22,18 +22,20 @@ class PlatformHelperTest extends Specification {
         this.helper.getOsName() == osName
         this.helper.getOsArch() == osArch
         this.helper.isWindows() == isWindows
+        this.helper.isSupported() == isSupported
 
         where:
-        osProp      | archProp  | osName   | osArch    | isWindows
-        'Windows 8' | 'x86'     | 'win'    | 'x86'     | true
-        'Windows 8' | 'x86_64'  | 'win'    | 'x64'     | true
-        'Mac OS X'  | 'x86'     | 'darwin' | 'x86'     | false
-        'Mac OS X'  | 'x86_64'  | 'darwin' | 'x64'     | false
-        'Linux'     | 'x86'     | 'linux'  | 'x86'     | false
-        'Linux'     | 'x86_64'  | 'linux'  | 'x64'     | false
-        'Linux'     | 'ppc64le' | 'linux'  | 'ppc64le' | false
-        'SunOS'     | 'x86'     | 'sunos'  | 'x86'     | false
-        'SunOS'     | 'x86_64'  | 'sunos'  | 'x64'     | false
+        osProp      | archProp  | osName        | osArch    | isWindows | isSupported
+        'Windows 8' | 'x86'     | 'win'         | 'x86'     | true      | true
+        'Windows 8' | 'x86_64'  | 'win'         | 'x64'     | true      | true
+        'Mac OS X'  | 'x86'     | 'darwin'      | 'x86'     | false     | true
+        'Mac OS X'  | 'x86_64'  | 'darwin'      | 'x64'     | false     | true
+        'Linux'     | 'x86'     | 'linux'       | 'x86'     | false     | true
+        'Linux'     | 'x86_64'  | 'linux'       | 'x64'     | false     | true
+        'Linux'     | 'ppc64le' | 'linux'       | 'ppc64le' | false     | true
+        'SunOS'     | 'x86'     | 'sunos'       | 'x86'     | false     | true
+        'SunOS'     | 'x86_64'  | 'sunos'       | 'x64'     | false     | true
+        'FreeBSD'   | 'amd64'   | 'unsupported' | 'x64'     | false     | false
     }
 
     @Unroll
@@ -62,7 +64,7 @@ class PlatformHelperTest extends Specification {
         this.props.setProperty("os.name", 'Nonsense')
 
         when:
-        this.helper.getOsName()
+        this.helper.failOnUnsupportedOs()
 
         then:
         thrown(IllegalStateException)