From e2623b7d35fe1d9b8ab984349678072a533ff61a Mon Sep 17 00:00:00 2001
From: Phillip Webb <pwebb@pivotal.io>
Date: Tue, 12 Jun 2018 21:17:50 -0700
Subject: [PATCH] Add profile expression support

Allow the `Environment` to accept a generic `Profiles` interface which
can support more complex matching rules. The previous
`acceptsProfiles(String...)` method now uses `Profiles.of` which
supports basic profile expressions such as "(a | b) & !c"

Issue: SPR-12458
---
 .../core/env/AbstractEnvironment.java         |  18 +-
 .../springframework/core/env/Environment.java |  20 +-
 .../springframework/core/env/Profiles.java    |  76 ++++++
 .../core/env/ProfilesParser.java              | 155 ++++++++++++
 .../core/env/DummyEnvironment.java            |   5 +-
 .../core/env/ProfilesTests.java               | 222 ++++++++++++++++++
 .../core/env/StandardEnvironmentTests.java    |  12 +-
 7 files changed, 481 insertions(+), 27 deletions(-)
 create mode 100644 spring-core/src/main/java/org/springframework/core/env/Profiles.java
 create mode 100644 spring-core/src/main/java/org/springframework/core/env/ProfilesParser.java
 create mode 100644 spring-core/src/test/java/org/springframework/core/env/ProfilesTests.java

diff --git a/spring-core/src/main/java/org/springframework/core/env/AbstractEnvironment.java b/spring-core/src/main/java/org/springframework/core/env/AbstractEnvironment.java
index b50b8b8242..94d82e2db7 100644
--- a/spring-core/src/main/java/org/springframework/core/env/AbstractEnvironment.java
+++ b/spring-core/src/main/java/org/springframework/core/env/AbstractEnvironment.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -323,19 +323,9 @@ public abstract class AbstractEnvironment implements ConfigurableEnvironment {
 	}
 
 	@Override
-	public boolean acceptsProfiles(String... profiles) {
-		Assert.notEmpty(profiles, "Must specify at least one profile");
-		for (String profile : profiles) {
-			if (StringUtils.hasLength(profile) && profile.charAt(0) == '!') {
-				if (!isProfileActive(profile.substring(1))) {
-					return true;
-				}
-			}
-			else if (isProfileActive(profile)) {
-				return true;
-			}
-		}
-		return false;
+	public boolean acceptsProfiles(Profiles profiles) {
+		Assert.notNull(profiles, "Profiles must not be null");
+		return profiles.matches(this::isProfileActive);
 	}
 
 	/**
diff --git a/spring-core/src/main/java/org/springframework/core/env/Environment.java b/spring-core/src/main/java/org/springframework/core/env/Environment.java
index 52c8717e94..d335aa9db5 100644
--- a/spring-core/src/main/java/org/springframework/core/env/Environment.java
+++ b/spring-core/src/main/java/org/springframework/core/env/Environment.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -97,15 +97,19 @@ public interface Environment extends PropertyResolver {
 	/**
 	 * Return whether one or more of the given profiles is active or, in the case of no
 	 * explicit active profiles, whether one or more of the given profiles is included in
-	 * the set of default profiles. If a profile begins with '!' the logic is inverted,
-	 * i.e. the method will return true if the given profile is <em>not</em> active.
-	 * For example, <pre class="code">env.acceptsProfiles("p1", "!p2")</pre> will
-	 * return {@code true} if profile 'p1' is active or 'p2' is not active.
-	 * @throws IllegalArgumentException if called with zero arguments
-	 * or if any profile is {@code null}, empty or whitespace-only
+	 * the set of default profiles. Profiles can simple indicators ('{@code p1}',
+	 * {@code !p1}) or more complex boolean expressions. See {@link Profiles#of(String...)}
+	 * for syntax details.
 	 * @see #getActiveProfiles
 	 * @see #getDefaultProfiles
 	 */
-	boolean acceptsProfiles(String... profiles);
+	default boolean acceptsProfiles(String... profiles) {
+		return acceptsProfiles(Profiles.of(profiles));
+	}
+
+	/**
+	 * Returns whether the active profiles match the given {@link Profiles} set.
+	 */
+	boolean acceptsProfiles(Profiles profiles);
 
 }
diff --git a/spring-core/src/main/java/org/springframework/core/env/Profiles.java b/spring-core/src/main/java/org/springframework/core/env/Profiles.java
new file mode 100644
index 0000000000..dd09d7b504
--- /dev/null
+++ b/spring-core/src/main/java/org/springframework/core/env/Profiles.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.env;
+
+/**
+ * A set of profiles that may be {@link Environment#acceptsProfiles(Profiles) accepted} by
+ * an {@link Environment}.
+ * <p>
+ * May be implemented directly or, more usually, created using the {@link #of(String...)
+ * of(...)} factory method.
+ *
+ * @author Phillip Webb
+ * @since 5.0
+ * @see #of(String...)
+ */
+@FunctionalInterface
+public interface Profiles {
+
+	/**
+	 * Test if this profile set matches against given active profiles.
+	 */
+	boolean matches(ActiveProfiles activeProfiles);
+
+	/**
+	 * Return a new {@link Profiles} instance that checks for matches against the given
+	 * profile strings. The returned instance will
+	 * {@link Profiles#matches(ActiveProfiles) matches} if any one of the given profile
+	 * strings match.
+	 * <p>
+	 * A profile string may contains a simple profile name (for example
+	 * {@code "production"}) or a profile expression. A profile expression allows for more
+	 * complicated profile logic to be expressed, for example
+	 * {@code "production & cloud"}.
+	 * <p>
+	 * The following operators are supported in profile expressions:
+	 * <ul>
+	 * <li>{@code !} - A logical <em>not</em> of the profile</li>
+	 * <li>{@code &} - A logical <em>and</em> of the profiles</li>
+	 * <li>{@code |} - A logical <em>or</em> of the profiles</li></li>
+	 * <p>
+	 * Please note that the {@code &} and {@code |} operators may not be mixed without
+	 * using parentheses. For example {@code "a & b | c"} is not a valid expression, it
+	 * must be expressed as {@code "(a & b) | c"}.
+	 *
+	 * @param profiles the profiles to include
+	 * @return a new {@link Profiles} instance
+	 */
+	public static Profiles of(String... profiles) {
+		return ProfilesParser.parse(profiles);
+	}
+
+	/**
+	 * The current set of active profiles.
+	 */
+	interface ActiveProfiles {
+
+		/**
+		 * Tests if given profile is currently active.
+		 */
+		boolean contains(String profile);
+	}
+}
diff --git a/spring-core/src/main/java/org/springframework/core/env/ProfilesParser.java b/spring-core/src/main/java/org/springframework/core/env/ProfilesParser.java
new file mode 100644
index 0000000000..bb1bd857f9
--- /dev/null
+++ b/spring-core/src/main/java/org/springframework/core/env/ProfilesParser.java
@@ -0,0 +1,155 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.env;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.StringTokenizer;
+import java.util.function.Predicate;
+
+import org.springframework.core.env.Profiles.ActiveProfiles;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Internal parser used by {@link Profiles#of}.
+ *
+ * @author Phillip Webb
+ * @since 5.0
+ */
+class ProfilesParser {
+
+	public static Profiles parse(String... expressions) {
+		Assert.notEmpty(expressions, "Must specify at least one profile");
+		Profiles[] parsed = new Profiles[expressions.length];
+		for (int i = 0; i < expressions.length; i++) {
+			parsed[i] = parseExpression(expressions[i]);
+		}
+		return new ParsedProfiles(expressions, parsed);
+	}
+
+	private static Profiles parseExpression(String expression) {
+		Assert.hasText(expression,
+				"Invalid profile expression [" + expression + "]: must contain text");
+		StringTokenizer tokens = new StringTokenizer(expression, "()&|!", true);
+		return parseTokens(expression, tokens);
+	}
+
+	private static Profiles parseTokens(String expression, StringTokenizer tokens) {
+		List<Profiles> elements = new ArrayList<>();
+		Operator operator = null;
+		while (tokens.hasMoreTokens()) {
+			String token = tokens.nextToken().trim();
+			if(token.isEmpty()) {
+				continue;
+			}
+			switch (token) {
+				case "(":
+					elements.add(parseTokens(expression, tokens));
+					break;
+				case "&":
+					assertWellFormed(expression, operator == null || operator == Operator.AND);
+					operator = Operator.AND;
+					break;
+				case "|":
+					assertWellFormed(expression, operator == null || operator == Operator.OR);
+					operator = Operator.OR;
+					break;
+				case "!":
+					elements.add(not(parseTokens(expression, tokens)));
+					break;
+				case ")":
+					Profiles merged = merge(expression, elements, operator);
+					elements.clear();
+					elements.add(merged);
+					operator = null;
+					break;
+				default:
+					elements.add(equals(token));
+			}
+		}
+		return merge(expression, elements, operator);
+	}
+
+	private static Profiles merge(String expression, List<Profiles> elements, Operator operator) {
+		assertWellFormed(expression, !elements.isEmpty());
+		if (elements.size() == 1) {
+			return elements.get(0);
+		}
+		Profiles[] profiles = elements.toArray(new Profiles[0]);
+		return (operator != Operator.AND ? or(profiles) : and(profiles));
+	}
+
+	private static void assertWellFormed(String expression, boolean wellFormed) {
+		Assert.isTrue(wellFormed,
+				() -> "Malformed profile expression '" + expression + "'");
+	}
+
+	private static Profiles or(Profiles... profiles) {
+		return (activeProfile) -> Arrays.stream(profiles).anyMatch(
+				isMatch(activeProfile));
+	}
+
+	private static Profiles and(Profiles... profiles) {
+		return (activeProfile) -> Arrays.stream(profiles).allMatch(
+				isMatch(activeProfile));
+	}
+
+	private static Profiles not(Profiles profiles) {
+		return (activeProfiles) -> !profiles.matches(activeProfiles);
+	}
+
+	private static Profiles equals(String profile) {
+		return (activeProfile) -> activeProfile.contains(profile);
+	}
+
+	private static Predicate<Profiles> isMatch(ActiveProfiles activeProfile) {
+		return (profiles) -> profiles.matches(activeProfile);
+	}
+
+	enum Operator {
+		AND, OR
+	};
+
+	private static class ParsedProfiles implements Profiles {
+
+		private final String[] expressions;
+
+		private final Profiles[] parsed;
+
+		public ParsedProfiles(String[] expressions, Profiles[] parsed) {
+			this.expressions = expressions;
+			this.parsed = parsed;
+		}
+
+		@Override
+		public boolean matches(ActiveProfiles activeProfiles) {
+			for (Profiles candidate : this.parsed) {
+				if (candidate.matches(activeProfiles)) {
+					return true;
+				}
+			}
+			return false;
+		}
+
+		@Override
+		public String toString() {
+			return StringUtils.arrayToCommaDelimitedString(this.expressions);
+		}
+	}
+}
diff --git a/spring-core/src/test/java/org/springframework/core/env/DummyEnvironment.java b/spring-core/src/test/java/org/springframework/core/env/DummyEnvironment.java
index b74aa9ebc4..aa26747623 100644
--- a/spring-core/src/test/java/org/springframework/core/env/DummyEnvironment.java
+++ b/spring-core/src/test/java/org/springframework/core/env/DummyEnvironment.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -74,8 +74,7 @@ public class DummyEnvironment implements Environment {
 	}
 
 	@Override
-	public boolean acceptsProfiles(String... profiles) {
+	public boolean acceptsProfiles(Profiles profiles) {
 		return false;
 	}
-
 }
diff --git a/spring-core/src/test/java/org/springframework/core/env/ProfilesTests.java b/spring-core/src/test/java/org/springframework/core/env/ProfilesTests.java
new file mode 100644
index 0000000000..13c7d659dc
--- /dev/null
+++ b/spring-core/src/test/java/org/springframework/core/env/ProfilesTests.java
@@ -0,0 +1,222 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.env;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.function.Supplier;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.springframework.core.env.Profiles.ActiveProfiles;
+import org.springframework.util.StringUtils;
+
+import static org.junit.Assert.*;
+
+/**
+ * Tests for {@link Profiles}.
+ *
+ * @author Phillip Webb
+ */
+public class ProfilesTests {
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	@Test
+	public void ofWhenNullThrowsException() {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("Must specify at least one profile");
+		Profiles.of((String[]) null);
+	}
+
+	@Test
+	public void ofWhenEmptyThrowsException() {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("Must specify at least one profile");
+		Profiles.of();
+	}
+
+	@Test
+	public void ofNullElement() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("must contain text");
+		Profiles.of((String)null);
+	}
+
+	@Test
+	public void ofSingleElement() {
+		Profiles profiles = Profiles.of("spring");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertFalse(profiles.matches(new MockActiveProfiles("framework")));
+	}
+
+	@Test
+	public void ofSingleInvertedElement() {
+		Profiles profiles = Profiles.of("!spring");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+	}
+
+	@Test
+	public void ofMultipleElements() {
+		Profiles profiles = Profiles.of("spring", "framework");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofMultipleElementsWithInverted() {
+		Profiles profiles = Profiles.of("!spring", "framework");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "framework")));
+	}
+
+	@Test
+	public void ofMultipleElementsAllInverted() {
+		Profiles profiles = Profiles.of("!spring", "!framework");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertFalse(
+				profiles.matches(new MockActiveProfiles("spring", "framework", "java")));
+	}
+
+	@Test
+	public void ofSingleExpression() throws Exception {
+		Profiles profiles = Profiles.of("(spring)");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertFalse(profiles.matches(new MockActiveProfiles("framework")));
+	}
+
+	@Test
+	public void ofSingleInvertedExpression() throws Exception {
+		Profiles profiles = Profiles.of("(!spring)");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+	}
+
+	@Test
+	public void ofOrExpression() throws Exception {
+		Profiles profiles = Profiles.of("(spring | framework)");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofAndExpression() throws Exception {
+		Profiles profiles = Profiles.of("(spring & framework)");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertFalse(profiles.matches(new MockActiveProfiles("framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofAndExpressionWithoutBraces() throws Exception {
+		Profiles profiles = Profiles.of("spring & framework");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertFalse(profiles.matches(new MockActiveProfiles("framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofNotAndExpression() throws Exception {
+		Profiles profiles = Profiles.of("!(spring & framework)");
+		assertTrue(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofNotOrExpression() throws Exception {
+		Profiles profiles = Profiles.of("!(spring | framework)");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertFalse(profiles.matches(new MockActiveProfiles("framework")));
+		assertFalse(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("java")));
+	}
+
+	@Test
+	public void ofComplex() throws Exception {
+		Profiles profiles = Profiles.of("(spring & framework) | (spring & java)");
+		assertFalse(profiles.matches(new MockActiveProfiles("spring")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "framework")));
+		assertTrue(profiles.matches(new MockActiveProfiles("spring", "java")));
+		assertFalse(profiles.matches(new MockActiveProfiles("java", "framework")));
+	}
+
+	@Test
+	public void malformedExpressions() throws Exception {
+		assertMalformed(() -> Profiles.of("("));
+		assertMalformed(() -> Profiles.of(")"));
+		assertMalformed(() -> Profiles.of("a & b | c"));
+	}
+
+	private void assertMalformed(Supplier<Profiles> supplier) {
+		try {
+			supplier.get();
+			fail("Not malformed");
+		}
+		catch (IllegalArgumentException ex) {
+			assertTrue(ex.getMessage().contains("Malformed"));
+		}
+	}
+
+	private static class MockActiveProfiles implements ActiveProfiles {
+
+		private Set<String> activeProfiles;
+
+		private Set<String> defaultProfiles;
+
+
+		public MockActiveProfiles(String... activeProfiles) {
+			this(Arrays.asList(activeProfiles));
+		}
+
+		public MockActiveProfiles(Collection<String> activeProfiles) {
+			this(activeProfiles, Collections.singleton("default"));
+		}
+
+		public MockActiveProfiles(Collection<String> activeProfiles,
+				Collection<String> defaultProfiles) {
+			this.activeProfiles = new LinkedHashSet<>(activeProfiles);
+			this.defaultProfiles = new LinkedHashSet<>(defaultProfiles);
+		}
+
+
+		@Override
+		public boolean contains(String profile) {
+			if (!StringUtils.hasText(profile) || profile.charAt(0) == '!') {
+				throw new IllegalArgumentException("Invalid profile [" + profile + "]");
+			}
+			return (this.activeProfiles.contains(profile)
+					|| (this.activeProfiles.isEmpty() && this.defaultProfiles.contains(profile)));
+		}
+	}
+
+}
diff --git a/spring-core/src/test/java/org/springframework/core/env/StandardEnvironmentTests.java b/spring-core/src/test/java/org/springframework/core/env/StandardEnvironmentTests.java
index 0ffb1fd132..0f0266b8f0 100644
--- a/spring-core/src/test/java/org/springframework/core/env/StandardEnvironmentTests.java
+++ b/spring-core/src/test/java/org/springframework/core/env/StandardEnvironmentTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -283,7 +283,6 @@ public class StandardEnvironmentTests {
 		environment.acceptsProfiles("");
 	}
 
-
 	@Test
 	public void acceptsProfiles_activeProfileSetProgrammatically() {
 		assertThat(environment.acceptsProfiles("p1", "p2"), is(false));
@@ -326,6 +325,15 @@ public class StandardEnvironmentTests {
 		environment.acceptsProfiles("p1", "!");
 	}
 
+	@Test
+	public void acceptsProfiles_withProfileExpression() throws Exception {
+		assertThat(environment.acceptsProfiles("p1 & p2"), is(false));
+		environment.addActiveProfile("p1");
+		assertThat(environment.acceptsProfiles("p1 & p2"), is(false));
+		environment.addActiveProfile("p2");
+		assertThat(environment.acceptsProfiles("p1 & p2"), is(true));
+	}
+
 	@Test
 	public void environmentSubclass_withCustomProfileValidation() {
 		ConfigurableEnvironment env = new AbstractEnvironment() {