From ddbecf62b3ed07422ab8863b12fd01b85c432180 Mon Sep 17 00:00:00 2001
From: Phillip Webb <pwebb@vmware.com>
Date: Mon, 8 Jun 2020 11:06:01 -0700
Subject: [PATCH] Polish 'Fix Mustache to not ignore native fetcher'

See gh-21060
---
 .../MustacheEnvironmentCollector.java         | 43 ++++++++++---------
 .../MustacheStandaloneIntegrationTests.java   | 18 ++++----
 2 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mustache/MustacheEnvironmentCollector.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mustache/MustacheEnvironmentCollector.java
index 1abe4e3a57..c9d0cebfbd 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mustache/MustacheEnvironmentCollector.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mustache/MustacheEnvironmentCollector.java
@@ -43,9 +43,9 @@ public class MustacheEnvironmentCollector extends DefaultCollector implements En
 
 	@Override
 	public VariableFetcher createFetcher(Object ctx, String name) {
-		VariableFetcher fetcher = super.createFetcher(ctx, name);
-		if (fetcher != null) {
-			return new PropertyVariableFetcher(fetcher);
+		VariableFetcher nativeFetcher = super.createFetcher(ctx, name);
+		if (nativeFetcher != null) {
+			return new PropertyVariableFetcher(nativeFetcher);
 		}
 		if (this.environment.containsProperty(name)) {
 			return new PropertyVariableFetcher();
@@ -53,6 +53,9 @@ public class MustacheEnvironmentCollector extends DefaultCollector implements En
 		return null;
 	}
 
+	/**
+	 * {@link VariableFetcher} that also checks the {@link Environment}.
+	 */
 	private class PropertyVariableFetcher implements VariableFetcher {
 
 		private final VariableFetcher nativeFetcher;
@@ -61,29 +64,29 @@ public class MustacheEnvironmentCollector extends DefaultCollector implements En
 			this.nativeFetcher = null;
 		}
 
-		PropertyVariableFetcher(VariableFetcher nativeFetcher) {
-			this.nativeFetcher = nativeFetcher;
+		PropertyVariableFetcher(VariableFetcher delegate) {
+			this.nativeFetcher = delegate;
 		}
 
 		@Override
 		public Object get(Object ctx, String name) {
-			Object result;
-			if (this.nativeFetcher != null) {
-				try {
-					result = this.nativeFetcher.get(ctx, name);
-					if (result != null && result != Template.NO_FETCHER_FOUND) {
-						return result;
-					}
-				}
-				catch (Exception ex) {
-					// fall through
-				}
+			Object result = getFromNativeFetcher(ctx, name);
+			result = (result != null) ? result : getFromEnvironment(name);
+			return (result != null) ? result : Template.NO_FETCHER_FOUND;
+		}
+
+		private Object getFromNativeFetcher(Object ctx, String name) {
+			try {
+				Object result = (this.nativeFetcher != null) ? this.nativeFetcher.get(ctx, name) : null;
+				return (result != Template.NO_FETCHER_FOUND) ? result : null;
 			}
-			result = MustacheEnvironmentCollector.this.environment.getProperty(name);
-			if (result == null) {
-				return Template.NO_FETCHER_FOUND;
+			catch (Exception ex) {
+				return null;
 			}
-			return result;
+		}
+
+		private Object getFromEnvironment(String name) {
+			return MustacheEnvironmentCollector.this.environment.getProperty(name);
 		}
 
 	}
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mustache/MustacheStandaloneIntegrationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mustache/MustacheStandaloneIntegrationTests.java
index 620fe0efb2..7c1efa729c 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mustache/MustacheStandaloneIntegrationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mustache/MustacheStandaloneIntegrationTests.java
@@ -68,14 +68,14 @@ class MustacheStandaloneIntegrationTests {
 
 	@Test
 	void environmentCollectorCompoundKeyWithBean() {
-		assertThat(this.compiler.compile("Hello: {{foo.name}}")
-				.execute(Collections.singletonMap("foo", new Foo()))).isEqualTo("Hello: Foo");
+		assertThat(this.compiler.compile("Hello: {{foo.name}}").execute(Collections.singletonMap("foo", new Foo())))
+				.isEqualTo("Hello: Foo");
 	}
 
 	@Test
 	void environmentCollectorCompoundKeyWithBeanPrefersEnvironment() {
-		assertThat(this.compiler.compile("Hello: {{bar.name}}")
-				.execute(Collections.singletonMap("bar", new Foo()))).isEqualTo("Hello: Bar");
+		assertThat(this.compiler.compile("Hello: {{bar.name}}").execute(Collections.singletonMap("bar", new Foo())))
+				.isEqualTo("Hello: Bar");
 	}
 
 	@Test
@@ -94,17 +94,19 @@ class MustacheStandaloneIntegrationTests {
 	static class Application {
 
 	}
-	
+
 	static class Foo {
+
 		private String name = "Foo";
 
-		public String getName() {
-			return name;
+		String getName() {
+			return this.name;
 		}
 
-		public void setName(String name) {
+		void setName(String name) {
 			this.name = name;
 		}
+
 	}
 
 }