Add CelMutableIdent

common/src/main/java/dev/cel/common/ast/CelMutableExpr.java

@@ -15,6 +15,7 @@
 package dev.cel.common.ast;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 import dev.cel.common.ast.CelExpr.CelNotSet;
 import dev.cel.common.ast.CelExpr.ExprKind;
@@ -34,6 +35,7 @@ public final class CelMutableExpr {
   private ExprKind.Kind exprKind;
   private CelNotSet notSet;
   private CelConstant constant;
+  private CelMutableIdent ident;
   private int hash = 0;
 
   public long id() {
@@ -58,17 +60,58 @@ public CelConstant constant() {
     return constant;
   }
 
+  public CelMutableIdent ident() {
+    checkExprKind(Kind.IDENT);
+    return ident;
+  }
+
   public void setConstant(CelConstant constant) {
     this.exprKind = ExprKind.Kind.CONSTANT;
-    this.constant = constant;
+    this.constant = checkNotNull(constant);
   }
 
-  public static CelMutableExpr ofConstant(CelConstant constant) {
-    return ofConstant(0L, constant);
+  public void setIdent(CelMutableIdent ident) {
+    this.exprKind = ExprKind.Kind.IDENT;
+    this.ident = checkNotNull(ident);
   }
 
-  public static CelMutableExpr ofConstant(long id, CelConstant constant) {
-    return new CelMutableExpr(id, constant);
+  /** A mutable identifier expression. */
+  public static final class CelMutableIdent {
+    private String name = "";
+
+    public String name() {
+      return name;
+    }
+
+    public void setName(String name) {
+      this.name = checkNotNull(name);
+    }
+
+    public static CelMutableIdent create(String name) {
+      return new CelMutableIdent(name);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (obj == this) {
+        return true;
+      }
+      if (obj instanceof CelMutableIdent) {
+        CelMutableIdent that = (CelMutableIdent) obj;
+        return this.name.equals(that.name);
+      }
+
+      return false;
+    }
+
+    @Override
+    public int hashCode() {
+      return name.hashCode();
+    }
+
+    private CelMutableIdent(String name) {
+      this.name = checkNotNull(name);
+    }
   }
 
   public static CelMutableExpr ofNotSet() {
@@ -79,11 +122,32 @@ public static CelMutableExpr ofNotSet(long id) {
     return new CelMutableExpr(id);
   }
 
+  public static CelMutableExpr ofConstant(CelConstant constant) {
+    return ofConstant(0L, constant);
+  }
+
+  public static CelMutableExpr ofConstant(long id, CelConstant constant) {
+    return new CelMutableExpr(id, constant);
+  }
+
+  public static CelMutableExpr ofIdent(String name) {
+    return ofIdent(0, name);
+  }
+
+  public static CelMutableExpr ofIdent(long id, String name) {
+    return new CelMutableExpr(id, CelMutableIdent.create(name));
+  }
+
   private CelMutableExpr(long id, CelConstant mutableConstant) {
     this.id = id;
     setConstant(mutableConstant);
   }
 
+  private CelMutableExpr(long id, CelMutableIdent mutableIdent) {
+    this.id = id;
+    setIdent(mutableIdent);
+  }
+
   private CelMutableExpr(long id) {
     this();
     this.id = id;
@@ -101,6 +165,7 @@ private Object exprValue() {
       case CONSTANT:
         return constant();
       case IDENT:
+        return ident();
       case SELECT:
       case CALL:
       case CREATE_LIST:

common/src/test/java/dev/cel/common/ast/CelMutableExprTest.java

@@ -21,6 +21,7 @@
 import com.google.testing.junit.testparameterinjector.TestParameter;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import dev.cel.common.ast.CelExpr.ExprKind.Kind;
+import dev.cel.common.ast.CelMutableExpr.CelMutableIdent;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -59,6 +60,31 @@ public void ofConstant_withId() {
     assertThat(mutableExpr.constant()).isEqualTo(CelConstant.ofValue(5L));
   }
 
+  @Test
+  public void ofIdent() {
+    CelMutableExpr mutableExpr = CelMutableExpr.ofIdent("x");
+
+    assertThat(mutableExpr.id()).isEqualTo(0L);
+    assertThat(mutableExpr.ident().name()).isEqualTo("x");
+  }
+
+  @Test
+  public void ofIdent_withId() {
+    CelMutableExpr mutableExpr = CelMutableExpr.ofIdent(1L, "x");
+
+    assertThat(mutableExpr.id()).isEqualTo(1L);
+    assertThat(mutableExpr.ident().name()).isEqualTo("x");
+  }
+
+  @Test
+  public void mutableIdent_setName() {
+    CelMutableIdent ident = CelMutableIdent.create("x");
+
+    ident.setName("y");
+
+    assertThat(ident.name()).isEqualTo("y");
+  }
+
   @Test
   public void setId_success() {
     CelMutableExpr mutableExpr = CelMutableExpr.ofConstant(CelConstant.ofValue(5L));
@@ -77,13 +103,17 @@ public void equalityTest() {
         .addEqualityGroup(
             CelMutableExpr.ofConstant(5L, CelConstant.ofValue("hello")),
             CelMutableExpr.ofConstant(5L, CelConstant.ofValue("hello")))
+        .addEqualityGroup(CelMutableExpr.ofIdent("x"))
+        .addEqualityGroup(CelMutableExpr.ofIdent(2L, "y"), CelMutableExpr.ofIdent(2L, "y"))
         .testEquals();
   }
 
   @SuppressWarnings("Immutable") // Mutable by design
   private enum MutableExprKindTestCase {
     NOT_SET(CelMutableExpr.ofNotSet(1L)),
-    CONSTANT(CelMutableExpr.ofConstant(CelConstant.ofValue(2L)));
+    CONSTANT(CelMutableExpr.ofConstant(CelConstant.ofValue(2L))),
+    IDENT(CelMutableExpr.ofIdent("test")),
+    ;
 
     private final CelMutableExpr mutableExpr;
 
@@ -101,12 +131,17 @@ public void getExprValue_invalidKind_throws(@TestParameter MutableExprKindTestCa
     if (!testCaseKind.equals(Kind.CONSTANT)) {
       assertThrows(IllegalArgumentException.class, testCase.mutableExpr::constant);
     }
+    if (!testCaseKind.equals(Kind.IDENT)) {
+      assertThrows(IllegalArgumentException.class, testCase.mutableExpr::ident);
+    }
   }
 
   @SuppressWarnings("Immutable") // Mutable by design
   private enum HashCodeTestCase {
     NOT_SET(CelMutableExpr.ofNotSet(1L), -722379961),
-    CONSTANT(CelMutableExpr.ofConstant(2L, CelConstant.ofValue("test")), -724279919);
+    CONSTANT(CelMutableExpr.ofConstant(2L, CelConstant.ofValue("test")), -724279919),
+    IDENT(CelMutableExpr.ofIdent("x"), -721379855),
+    ;
 
     private final CelMutableExpr mutableExpr;
     private final int expectedHashCode;