Use code snippet instead of link for hermetic Gradle script

_posts/2017-03-01-hermetic-builds.md

@@ -7,7 +7,119 @@ Robolectric needs access to multiple Android SDK jars in order to perform its ma
 
 But what if you have a [hermetic build environment](http://blog.fahhem.com/2013/12/hermetic-build-systems/)? You just need to do a little more configuration.
 
-Here's a [Gradle build script](https://gist.github.com/xian/05c4f27da6d4156b9827842217c2cd5c) that'll help.
+Here's a Gradle build script that'll help:
+
+```Groovy
+def robolectricVersion = '3.3'
+
+def androidSdkVersions = [
+        '4.1.2_r1-robolectric-0',
+        '4.2.2_r1.2-robolectric-0',
+        '4.3_r2-robolectric-0',
+        '4.4_r1-robolectric-1',
+        '5.0.0_r2-robolectric-1',
+        '5.1.1_r9-robolectric-1',
+        '6.0.0_r1-robolectric-0',
+        '6.0.1_r3-robolectric-0',
+        '7.0.0_r1-robolectric-0',
+        '7.1.0_r7-robolectric-0',
+]
+
+def shadowArtifacts = [
+        "org.robolectric:shadows-core:${robolectricVersion}",
+        "org.robolectric:shadows-httpclient:${robolectricVersion}",
+        "org.robolectric:shadows-maps:${robolectricVersion}",
+        "org.robolectric:shadows-multidex:${robolectricVersion}",
+        "org.robolectric:shadows-play-services:${robolectricVersion}",
+        "org.robolectric:shadows-support-v4:${robolectricVersion}",
+]
+
+apply plugin: 'java'
+
+repositories {
+    mavenLocal()
+    jcenter()
+}
+
+configurations {
+    sandbox
+}
+
+def allSdkConfigurations = []
+
+androidSdkVersions.forEach { version ->
+    allSdkConfigurations << configurations.create(version)
+    dependencies.add(version, "org.robolectric:android-all:${version}")
+    dependencies.add('sandbox', "org.robolectric:android-all:${version}")
+}
+
+
+// In this section you declare the dependencies for your production and test code
+dependencies {
+    compile("org.robolectric:robolectric:${robolectricVersion}") {
+        // we don't need these MavenDependencyResolver in a hermetic build
+        exclude group: 'org.apache.maven', module: 'maven-ant-tasks'
+        exclude group: 'org.apache.ant', module: 'ant'
+    }
+
+    shadowArtifacts.forEach { shadowArtifact ->
+        compile shadowArtifact
+        sandbox shadowArtifact
+    }
+}
+
+
+task createRobolectricDeps {
+}
+
+task copyLibs(type: Copy) {
+    into "$buildDir/output/libs"
+    from configurations.compile
+
+    doLast {
+        def f = new File("$buildDir/output/README.txt")
+        f.delete()
+
+        f << "# Include the following jar files on your classpath:\n"
+        f << "#\n"
+
+        source.forEach { file ->
+            f << "libs/${file.name}\n"
+        }
+    }
+}
+
+task copySdks(type: Copy) {
+    into "$buildDir/output/libs"
+    from allSdkConfigurations
+
+    doLast {
+        def f = new File("$buildDir/output/robolectric-deps.properties")
+        f.delete()
+
+        f << "# Place this file in your test resources dir (e.g. src/test/resources).\n"
+        f << "# Paths below should be absolute, or relative to this file.\n"
+        f << "#\n"
+
+        allSdkConfigurations.forEach { config ->
+            config.allDependencies.forEach { dep ->
+                def files = new ArrayList(config.files)
+                if (files.size != 1) {
+                    throw new RuntimeException("huh, more than one file in ${dep}? ${files}")
+                }
+                def file = files[0]
+                f << "${dep.group}\\:${dep.name}\\:${dep.version}=path/to/${file.name}\n"
+            }
+        }
+    }
+}
+
+task filesForHermeticBuild {
+    dependsOn createRobolectricDeps
+    dependsOn copyLibs
+    dependsOn copySdks
+}
+```
 
 1. Create an empty Gradle project (either `gradle init` or use Android Studio or IntelliJ).
 1. Paste the script into your `build.gradle`.