From 51c9a94fa6429fbc31842af476173a52faecf4f4 Mon Sep 17 00:00:00 2001
From: Martin Monperrus <monperrus@users.noreply.github.com>
Date: Mon, 2 Oct 2017 09:45:21 +0200
Subject: [PATCH] feat: add a static method to getting started with one single
 line of code (#1559)

* feat: add a static method to getting started with one single line of code

* up

* up
---
 README.md                                 |  5 +++++
 doc/launcher.md                           |  8 +++++++-
 src/main/java/spoon/Launcher.java         | 18 ++++++++++++++++++
 src/test/java/spoon/test/api/APITest.java | 10 ++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 97d89346eba..7104a4501c4 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,11 @@
 # Spoon
 
 Spoon is an open-source library to analyze, rewrite, transform, transpile Java source code. It parses source files to build a well-designed AST with powerful analysis and transformation API. It fully supports Java 8.
+
+```java
+CtClass l = Launcher.parseClass("class A { void m() { System.out.println(\"yeah\");} }");
+```
+
 External contributions as pull requests are welcome.
 The official website is available at <http://spoon.gforge.inria.fr/>.
 Spoon is an official Inria open-source project, and member of the [OW2](https://www.ow2.org/) open-source consortium.
diff --git a/doc/launcher.md b/doc/launcher.md
index 2acd0a23efa..a2f1dd2c054 100644
--- a/doc/launcher.md
+++ b/doc/launcher.md
@@ -6,7 +6,13 @@ keywords: usage, java
 
 ## Basic Launcher
 
-The Spoon `Launcher` ([JavaDoc](http://spoon.gforge.inria.fr/mvnsites/spoon-core/apidocs/spoon/Launcher.html)) is used to create the AST model of a project.
+The Spoon `Launcher` ([JavaDoc](http://spoon.gforge.inria.fr/mvnsites/spoon-core/apidocs/spoon/Launcher.html)) is used to create the AST model of a project. It can be as short as:
+
+```java
+CtClass l = Launcher.parseClass("class A { void m() { System.out.println(\"yeah\");} }");
+```
+
+The Launcher is highly configurable:
 
 ```java
 Launcher launcher = new Launcher();
diff --git a/src/main/java/spoon/Launcher.java b/src/main/java/spoon/Launcher.java
index 79fdb45abfb..aa5f8f9d828 100644
--- a/src/main/java/spoon/Launcher.java
+++ b/src/main/java/spoon/Launcher.java
@@ -34,6 +34,7 @@
 import spoon.compiler.SpoonResourceHelper;
 import spoon.processing.Processor;
 import spoon.reflect.CtModel;
+import spoon.reflect.declaration.CtClass;
 import spoon.reflect.declaration.CtElement;
 import spoon.reflect.declaration.CtType;
 import spoon.reflect.factory.Factory;
@@ -47,6 +48,7 @@
 import spoon.support.StandardEnvironment;
 import spoon.support.compiler.FileSystemFile;
 import spoon.support.compiler.FileSystemFolder;
+import spoon.support.compiler.VirtualFile;
 import spoon.support.compiler.jdt.JDTBasedSpoonCompiler;
 import spoon.support.gui.SpoonModelTree;
 
@@ -798,4 +800,20 @@ public CtModel getModel() {
 		return factory.getModel();
 	}
 
+	/** returns the AST of an inline class */
+	public static CtClass<?> parseClass(String code) {
+		Launcher launcher = new Launcher();
+		launcher.addInputResource(new VirtualFile(code));
+		launcher.getEnvironment().setNoClasspath(true);
+		launcher.getEnvironment().setAutoImports(true);
+		Collection<CtType<?>> allTypes = launcher.buildModel().getAllTypes();
+		if (allTypes.size() != 1) {
+			throw new SpoonException("parseClass only considers one class. Please consider using a Launcher object for more advanced usage.");
+		}
+		try {
+			return (CtClass<?>) allTypes.stream().findFirst().get();
+		} catch (ClassCastException e) {
+			throw new SpoonException("parseClass only considers classes (and not interfaces and enums). Please consider using a Launcher object for more advanced usage.");
+		}
+	}
 }
diff --git a/src/test/java/spoon/test/api/APITest.java b/src/test/java/spoon/test/api/APITest.java
index 9eafb5d8c5a..ba9bd3023d0 100644
--- a/src/test/java/spoon/test/api/APITest.java
+++ b/src/test/java/spoon/test/api/APITest.java
@@ -406,4 +406,14 @@ public void accept(CtVisitor visitor) {
 			assertEquals("Check the number of if in method " + statement.getParent(CtMethod.class).getSignature() + " in the declaring class " + statement.getParent(CtType.class).getQualifiedName(),1, matcher.find(ifCondition).size());
 		}
 	}
+
+	@Test
+	public void testOneLinerIntro() {
+		// contract: spoon can be used with a single line of code with Launcher.parseClass
+		CtClass<?> l = Launcher.parseClass("class A { void m() { System.out.println(\"yeah\");} }");
+		assertEquals("A", l.getSimpleName());
+		assertEquals(1, l.getMethods().size());
+		assertEquals("m", l.getMethodsByName("m").get(0).getSimpleName());
+		assertEquals("System.out.println(\"yeah\")", l.getMethodsByName("m").get(0).getBody().getStatement(0).toString());
+	}
 }