Make runIf more general

README.md

@@ -4,3 +4,64 @@
 Churros
 ====
 This is a humble library dedicated to making the life of developers easier.
+
+Installation
+====
+Be sure to have JCenter in the base gradle file.
+```groovy
+allprojects {
+    repositories {
+        jcenter()
+    }
+}
+```
+
+Then it's a matter of adding the dependency.
+```groovy
+dependencies {
+    // Churros
+    implementation "com.asapp.churros:churros:0.1.0"
+}
+```
+
+Things we have
+====
+* runIf
+```kotlin
+    val okHttpClient = OkHttpClient.Builder()
+        .addInterceptor(interceptor)
+        .runIf(isVerbose) {
+            val loggingInterceptor =
+                HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY)
+
+            addNetworkInterceptor(loggingInterceptor)
+        }
+        .build()
+```
+* exhaustive
+
+This code will work happily.
+```kotlin
+    enum class Snack {
+        HUMUS, CHIPS, GUACAMOLE
+    }
+    val today = GUACAMOLE
+
+    when (today) {
+        HUMUS -> getPita()
+        CHIPS -> buyGuacamole()
+    }
+```
+This code will complain that you missed thinking about Guacamole
+```kotlin
+    enum class Snack {
+        HUMUS, CHIPS, GUACAMOLE
+    }
+    val today = GUACAMOLE
+
+    when (today) {
+        HUMUS -> getPita()
+        CHIPS -> buyGuacamole()
+    }
+    .exhaustive()
+```

app/src/main/java/com/asapp/churros/AnyExtensions.kt

@@ -1,3 +1,17 @@
 package com.asapp.churros
 
-fun Any.exhaustive() {}
+/**
+ * exhaustive is meant to be used in combination with `when` to ensure all options are considered.
+ */
+fun Any.exhaustive() {}
+
+/**
+ * runIf preserves the chain in fluent APIs such as RxJava or the Builder pattern.
+ */
+fun <T> T.runIf(condition: Boolean, block: T.() -> T): T {
+    return if (condition) {
+        block()
+    } else {
+        this
+    }
+}

app/src/main/java/com/asapp/churros/rx/Extensions.kt

@@ -12,6 +12,7 @@ fun Disposable.disposeWith(disposableContainer: DisposableContainer) {
     disposableContainer.add(this)
 }
 
+@Deprecated("Use the simpler com.asapp.churros.runIf. Will be removed in the next mayor version.")
 fun <T> Single<T>.runIf(condition: Boolean, block: Single<T>.() -> Single<T>): Single<T> {
     return if (condition) {
         block()

app/src/test/java/com/asapp/churros/RunIfUnitTest.kt

@@ -0,0 +1,23 @@
+package com.asapp.churros
+
+import io.reactivex.Single
+import org.junit.Test
+
+class RunIfUnitTest {
+    @Test
+    fun testRunIf() {
+        Single.just(1)
+            .runIf(condition = true) {
+                map { 2 * it }
+            }
+            .test()
+            .assertValue(2)
+
+        Single.just(1)
+            .runIf(condition = false) {
+                map { 2 * it }
+            }
+            .test()
+            .assertValue(1)
+    }
+}