Better testing support

Add test apk field to the compiler options so that data binding
can know whether we are compiling a test apk for a library or
test apk for an app. This will allow us not to re-generate
data binding codes for test apks.

Bug: 24711174
Bug: 24670839
Change-Id: Ib00ff3148ce5a9f1ab0512c3821ea59a567401d5

2 files changed, 50 insertions, 6 deletions

diff --git a/compiler/src/main/kotlin/android/databinding/tool/writer/BRWriter.kt b/compiler/src/main/kotlin/android/databinding/tool/writer/BRWriter.kt
index a11804ff..885284ef 100644
--- a/compiler/src/main/kotlin/android/databinding/tool/writer/BRWriter.kt
+++ b/compiler/src/main/kotlin/android/databinding/tool/writer/BRWriter.kt
@@ -20,7 +20,7 @@ import android.databinding.tool.util.StringUtils
 
 class BRWriter(properties: Set<String>, val useFinal : Boolean) {
     val indexedProps = properties.sorted().withIndex()
-    public fun write(pkg : String): String = "package $pkg;${StringUtils.LINE_SEPARATOR}$klass"
+    fun write(pkg : String): String = "package $pkg;${StringUtils.LINE_SEPARATOR}$klass"
     val klass: String by lazy {
         kcode("") {
             val prefix = if (useFinal) "final " else "";
diff --git a/compiler/src/main/kotlin/android/databinding/tool/writer/DataBinderWriter.kt b/compiler/src/main/kotlin/android/databinding/tool/writer/BindingMapperWriter.kt
index 9bd06a00..0caf8a6f 100644
--- a/compiler/src/main/kotlin/android/databinding/tool/writer/DataBinderWriter.kt
+++ b/compiler/src/main/kotlin/android/databinding/tool/writer/BindingMapperWriter.kt
@@ -13,15 +13,39 @@
 
 package android.databinding.tool.writer
 
+import android.databinding.tool.DataBindingCompilerArgs
 import android.databinding.tool.LayoutBinder
 
-class DataBinderWriter(val pkg: String, val projectPackage: String, val className: String,
-        val layoutBinders : List<LayoutBinder>, val minSdk : kotlin.Int) {
+class BindingMapperWriter(var pkg : String, var className: String, val layoutBinders : List<LayoutBinder>,
+                          val compilerArgs: DataBindingCompilerArgs) {
+    private val appClassName : String = className
+    private val testClassName = "Test$className"
+    val generateAsTest = compilerArgs.isTestVariant && compilerArgs.isApp
+    val generateTestOverride = !generateAsTest && compilerArgs.isEnabledForTests
+    init {
+        if (generateAsTest) {
+            className = "Test${className}"
+        }
+    }
     fun write(brWriter : BRWriter) = kcode("") {
         nl("package $pkg;")
-        nl("import $projectPackage.BR;")
-        block("class $className") {
-            nl("final static int TARGET_MIN_SDK = $minSdk;")
+        nl("import ${compilerArgs.modulePackage}.BR;")
+        val extends = if (generateAsTest) "extends $appClassName" else ""
+        block("class $className $extends") {
+            nl("final static int TARGET_MIN_SDK = ${compilerArgs.minApi};")
+            if (generateTestOverride) {
+                nl("static $appClassName mTestOverride;")
+                block("static") {
+                    block("try") {
+                        nl("mTestOverride = ($appClassName)$appClassName.class.getClassLoader().loadClass(\"$pkg.$testClassName\").newInstance();")
+                    }
+                    block("catch(Throwable ignored)") {
+                        nl("// ignore, we are not running in test mode")
+                        nl("mTestOverride = null;")
+                    }
+
+                }
+            }
             nl("")
             block("public $className()") {
             }
@@ -58,6 +82,11 @@ class DataBinderWriter(val pkg: String, val projectPackage: String, val classNam
                         }
                     }
                 }
+                if (generateTestOverride) {
+                    block("if(mTestOverride != null)") {
+                        nl("return mTestOverride.getDataBinder(bindingComponent, view, layoutId);")
+                    }
+                }
                 nl("return null;")
             }
             block("android.databinding.ViewDataBinding getDataBinder(android.databinding.DataBindingComponent bindingComponent, android.view.View[] views, int layoutId)") {
@@ -80,6 +109,11 @@ class DataBinderWriter(val pkg: String, val projectPackage: String, val classNam
                         }
                     }
                 }
+                if (generateTestOverride) {
+                    block("if(mTestOverride != null)") {
+                        nl("return mTestOverride.getDataBinder(bindingComponent, views, layoutId);")
+                    }
+                }
                 nl("return null;")
             }
 
@@ -102,11 +136,21 @@ class DataBinderWriter(val pkg: String, val projectPackage: String, val classNam
 
                     }
                 }
+                if (generateTestOverride) {
+                    block("if(mTestOverride != null)") {
+                        nl("return mTestOverride.getLayoutId(tag);")
+                    }
+                }
                 nl("return 0;")
             }
 
             block("String convertBrIdToString(int id)") {
                 block("if (id < 0 || id >= InnerBrLookup.sKeys.length)") {
+                    if (generateTestOverride) {
+                        block("if(mTestOverride != null)") {
+                            nl("return mTestOverride.convertBrIdToString(id);")
+                        }
+                    }
                     nl("return null;")
                 }
                 nl("return InnerBrLookup.sKeys[id];")