Polish ExpressionState[Tests]

spring-expression/src/main/java/org/springframework/expression/spel/ExpressionState.java

@@ -93,6 +93,7 @@ public class ExpressionState {
 
 	public ExpressionState(EvaluationContext context, TypedValue rootObject, SpelParserConfiguration configuration) {
 		Assert.notNull(context, "EvaluationContext must not be null");
+		Assert.notNull(context, "'rootObject' must not be null");
 		Assert.notNull(configuration, "SpelParserConfiguration must not be null");
 		this.relatedContext = context;
 		this.rootObject = rootObject;
@@ -203,7 +204,7 @@ public class ExpressionState {
 	/*
 	 * A new scope is entered when a function is invoked.
 	 */
-	public void enterScope(Map<String, Object> argMap) {
+	public void enterScope(@Nullable Map<String, Object> argMap) {
 		initVariableScopes().push(new VariableScope(argMap));
 		initScopeRootObjects().push(getActiveContextObject());
 	}
@@ -300,9 +301,10 @@ public class ExpressionState {
 		}
 
 		public VariableScope(String name, Object value) {
-			this.vars.put(name,value);
+			this.vars.put(name, value);
 		}
 
+		@Nullable
 		public Object lookupVariable(String name) {
 			return this.vars.get(name);
 		}

spring-expression/src/test/java/org/springframework/expression/spel/ExpressionStateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.expression.spel;
 
-import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
@@ -34,27 +33,31 @@ import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
- * Tests for the expression state object - some features are not yet exploited in the language (eg nested scopes)
+ * Tests for {@link ExpressionState}.
+ *
+ * <p>Some features are not yet exploited in the language, such as nested scopes
+ * or local variables scoped to the currently evaluated expression.
+ *
+ * <p>Local variables are in variable scopes which come and go during evaluation.
+ * Normal/global variables are accessible through the {@link EvaluationContext}.
  *
  * @author Andy Clement
  * @author Juergen Hoeller
  */
-public class ExpressionStateTests extends AbstractExpressionTests {
+class ExpressionStateTests extends AbstractExpressionTests {
+
+	private ExpressionState state = new ExpressionState(TestScenarioCreator.getTestEvaluationContext());
+
 
 	@Test
-	public void testConstruction() {
+	void construction() {
 		EvaluationContext context = TestScenarioCreator.getTestEvaluationContext();
 		ExpressionState state = new ExpressionState(context);
 		assertThat(state.getEvaluationContext()).isEqualTo(context);
 	}
 
-	// Local variables are in variable scopes which come and go during evaluation.  Normal variables are
-	// accessible through the evaluation context
-
 	@Test
-	public void testLocalVariables() {
-		ExpressionState state = getState();
-
+	void localVariables() {
 		Object value = state.lookupLocalVariable("foo");
 		assertThat(value).isNull();
 
@@ -68,8 +71,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testVariables() {
-		ExpressionState state = getState();
+	void globalVariables() {
 		TypedValue typedValue = state.lookupVariable("foo");
 		assertThat(typedValue).isEqualTo(TypedValue.NULL);
 
@@ -85,8 +87,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testNoVariableInterference() {
-		ExpressionState state = getState();
+	void noVariableInterference() {
 		TypedValue typedValue = state.lookupVariable("foo");
 		assertThat(typedValue).isEqualTo(TypedValue.NULL);
 
@@ -99,8 +100,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testLocalVariableNestedScopes() {
-		ExpressionState state = getState();
+	void localVariableNestedScopes() {
 		assertThat(state.lookupLocalVariable("foo")).isNull();
 
 		state.setLocalVariable("foo",12);
@@ -120,30 +120,26 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testRootContextObject() {
-		ExpressionState state = getState();
+	void rootContextObject() {
 		assertThat(state.getRootContextObject().getValue().getClass()).isEqualTo(Inventor.class);
 
-		// although the root object is being set on the evaluation context, the value in the 'state' remains what it was when constructed
+		// Although the root object is being set on the evaluation context,
+		// the value in the 'state' remains what it was when constructed.
 		((StandardEvaluationContext) state.getEvaluationContext()).setRootObject(null);
-		assertThat(state.getRootContextObject().getValue().getClass()).isEqualTo(Inventor.class);
-		// assertEquals(null, state.getRootContextObject().getValue());
+		assertThat(state.getRootContextObject().getValue()).isInstanceOf(Inventor.class);
 
 		state = new ExpressionState(new StandardEvaluationContext());
 		assertThat(state.getRootContextObject()).isEqualTo(TypedValue.NULL);
 
-
 		((StandardEvaluationContext) state.getEvaluationContext()).setRootObject(null);
 		assertThat(state.getRootContextObject().getValue()).isNull();
 	}
 
 	@Test
-	public void testActiveContextObject() {
-		ExpressionState state = getState();
+	void activeContextObject() {
 		assertThat(state.getActiveContextObject().getValue()).isEqualTo(state.getRootContextObject().getValue());
 
-		assertThatIllegalStateException().isThrownBy(
-				state::popActiveContextObject);
+		assertThatIllegalStateException().isThrownBy(state::popActiveContextObject);
 
 		state.pushActiveContextObject(new TypedValue(34));
 		assertThat(state.getActiveContextObject().getValue()).isEqualTo(34);
@@ -162,8 +158,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testPopulatedNestedScopes() {
-		ExpressionState state = getState();
+	void populatedNestedScopes() {
 		assertThat(state.lookupLocalVariable("foo")).isNull();
 
 		state.enterScope("foo",34);
@@ -181,27 +176,22 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testRootObjectConstructor() {
-		EvaluationContext ctx = getContext();
+	void rootObjectConstructor() {
+		EvaluationContext ctx = TestScenarioCreator.getTestEvaluationContext();
 		// TypedValue root = ctx.getRootObject();
 		// supplied should override root on context
-		ExpressionState state = new ExpressionState(ctx,new TypedValue("i am a string"));
+		ExpressionState state = new ExpressionState(ctx, new TypedValue("i am a string"));
 		TypedValue stateRoot = state.getRootContextObject();
 		assertThat(stateRoot.getTypeDescriptor().getType()).isEqualTo(String.class);
 		assertThat(stateRoot.getValue()).isEqualTo("i am a string");
 	}
 
 	@Test
-	public void testPopulatedNestedScopesMap() {
-		ExpressionState state = getState();
+	void populatedNestedScopesMap() {
 		assertThat(state.lookupLocalVariable("foo")).isNull();
 		assertThat(state.lookupLocalVariable("goo")).isNull();
 
-		Map<String,Object> m = new HashMap<>();
-		m.put("foo", 34);
-		m.put("goo", "abc");
-
-		state.enterScope(m);
+		state.enterScope(Map.of("foo", 34, "goo", "abc"));
 		assertThat(state.lookupLocalVariable("foo")).isEqualTo(34);
 		assertThat(state.lookupLocalVariable("goo")).isEqualTo("abc");
 
@@ -217,61 +207,42 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testOperators() {
-		ExpressionState state = getState();
-		assertThatExceptionOfType(SpelEvaluationException.class).isThrownBy(() ->
-				state.operate(Operation.ADD,1,2))
+	void operators() {
+		assertThatExceptionOfType(SpelEvaluationException.class)
+			.isThrownBy(() -> state.operate(Operation.ADD,1,2))
 			.satisfies(ex -> assertThat(ex.getMessageCode()).isEqualTo(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES));
 
-		assertThatExceptionOfType(SpelEvaluationException.class).isThrownBy(() ->
-				state.operate(Operation.ADD,null,null))
+		assertThatExceptionOfType(SpelEvaluationException.class)
+			.isThrownBy(() -> state.operate(Operation.ADD,null,null))
 			.satisfies(ex -> assertThat(ex.getMessageCode()).isEqualTo(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES));
 	}
 
 	@Test
-	public void testComparator() {
-		ExpressionState state = getState();
+	void comparator() {
 		assertThat(state.getTypeComparator()).isEqualTo(state.getEvaluationContext().getTypeComparator());
 	}
 
 	@Test
-	public void testTypeLocator() throws EvaluationException {
-		ExpressionState state = getState();
+	void typeLocator() throws EvaluationException {
 		assertThat(state.getEvaluationContext().getTypeLocator()).isNotNull();
 		assertThat(state.findType("java.lang.Integer")).isEqualTo(Integer.class);
-		assertThatExceptionOfType(SpelEvaluationException.class).isThrownBy(() ->
-				state.findType("someMadeUpName"))
+		assertThatExceptionOfType(SpelEvaluationException.class)
+			.isThrownBy(() -> state.findType("someMadeUpName"))
 			.satisfies(ex -> assertThat(ex.getMessageCode()).isEqualTo(SpelMessage.TYPE_NOT_FOUND));
-
 	}
 
 	@Test
-	public void testTypeConversion() throws EvaluationException {
-		ExpressionState state = getState();
+	void typeConversion() throws EvaluationException {
 		String s = (String) state.convertValue(34, TypeDescriptor.valueOf(String.class));
 		assertThat(s).isEqualTo("34");
 
-		s = (String)state.convertValue(new TypedValue(34), TypeDescriptor.valueOf(String.class));
+		s = (String) state.convertValue(new TypedValue(34), TypeDescriptor.valueOf(String.class));
 		assertThat(s).isEqualTo("34");
 	}
 
 	@Test
-	public void testPropertyAccessors() {
-		ExpressionState state = getState();
+	void propertyAccessors() {
 		assertThat(state.getPropertyAccessors()).isEqualTo(state.getEvaluationContext().getPropertyAccessors());
 	}
 
-	/**
-	 * @return a new ExpressionState
-	 */
-	private ExpressionState getState() {
-		EvaluationContext context = TestScenarioCreator.getTestEvaluationContext();
-		ExpressionState state = new ExpressionState(context);
-		return state;
-	}
-
-	private EvaluationContext getContext() {
-		return TestScenarioCreator.getTestEvaluationContext();
-	}
-
 }