Enable conformance tests for two-var comprehensions.

bundle/src/test/java/dev/cel/bundle/CelEnvironmentExporterTest.java

@@ -110,7 +110,7 @@ public void standardLibrarySubset_favorExclusion() throws Exception {
                         FunctionSelector.create("matches", ImmutableSet.of()),
                         FunctionSelector.create(
                             "timestamp", ImmutableSet.of("string_to_timestamp"))))
-                .setExcludedMacros(ImmutableSet.of("map", "filter"))
+                .setExcludedMacros(ImmutableSet.of("map", "existsOne", "filter"))
                 .build());
   }
 

common/src/main/java/dev/cel/common/Operator.java

@@ -45,7 +45,9 @@ public enum Operator {
   HAS("has"),
   ALL("all"),
   EXISTS("exists"),
+  @Deprecated // Prefer EXISTS_ONE_NEW.
   EXISTS_ONE("exists_one"),
+  EXISTS_ONE_NEW("existsOne"),
   MAP("map"),
   FILTER("filter"),
   NOT_STRICTLY_FALSE("@not_strictly_false"),
@@ -109,6 +111,7 @@ public static Optional<Operator> find(String text) {
           .put(EQUALS.getFunction(), EQUALS)
           .put(EXISTS.getFunction(), EXISTS)
           .put(EXISTS_ONE.getFunction(), EXISTS_ONE)
+          .put(EXISTS_ONE_NEW.getFunction(), EXISTS_ONE_NEW)
           .put(FILTER.getFunction(), FILTER)
           .put(GREATER.getFunction(), GREATER)
           .put(GREATER_EQUALS.getFunction(), GREATER_EQUALS)

conformance/src/test/java/dev/cel/conformance/BUILD.bazel

@@ -22,6 +22,7 @@ java_library(
         "//common:options",
         "//common/types:cel_proto_types",
         "//compiler",
+        "//compiler:compiler_builder",
         "//extensions",
         "//extensions:optional_library",
         "//parser:macro",
@@ -49,6 +50,7 @@ java_library(
     tags = ["conformance_maven"],
     deps = MAVEN_JAR_DEPS + [
         "//:java_truth",
+        "//compiler:compiler_builder",
         "//testing:expr_value_utils",
         "@cel_spec//proto/cel/expr:expr_java_proto",
         "@cel_spec//proto/cel/expr/conformance/proto2:test_all_types_java_proto",
@@ -75,6 +77,7 @@ _ALL_TESTS = [
     "@cel_spec//tests/simple:testdata/lists.textproto",
     "@cel_spec//tests/simple:testdata/logic.textproto",
     "@cel_spec//tests/simple:testdata/macros.textproto",
+    "@cel_spec//tests/simple:testdata/macros2.textproto",
     "@cel_spec//tests/simple:testdata/math_ext.textproto",
     "@cel_spec//tests/simple:testdata/namespace.textproto",
     "@cel_spec//tests/simple:testdata/optionals.textproto",

conformance/src/test/java/dev/cel/conformance/ConformanceTest.java

@@ -35,6 +35,7 @@
 import dev.cel.common.CelValidationResult;
 import dev.cel.common.types.CelProtoTypes;
 import dev.cel.compiler.CelCompilerFactory;
+import dev.cel.compiler.CelCompilerLibrary;
 import dev.cel.expr.conformance.test.SimpleTest;
 import dev.cel.extensions.CelExtensions;
 import dev.cel.extensions.CelOptionalLibrary;
@@ -45,6 +46,7 @@
 import dev.cel.runtime.CelRuntime;
 import dev.cel.runtime.CelRuntime.Program;
 import dev.cel.runtime.CelRuntimeFactory;
+import dev.cel.runtime.CelRuntimeLibrary;
 import java.util.Map;
 import org.junit.runners.model.Statement;
 
@@ -61,31 +63,37 @@ public final class ConformanceTest extends Statement {
           .enableQuotedIdentifierSyntax(true)
           .build();
 
+  private static final ImmutableList<CelCompilerLibrary> CANONICAL_COMPILER_EXTENSIONS =
+      ImmutableList.of(
+          CelExtensions.bindings(),
+          CelExtensions.comprehensions(),
+          CelExtensions.encoders(OPTIONS),
+          CelExtensions.math(OPTIONS),
+          CelExtensions.protos(),
+          CelExtensions.sets(OPTIONS),
+          CelExtensions.strings(),
+          CelOptionalLibrary.INSTANCE);
+
+  private static final ImmutableList<CelRuntimeLibrary> CANONICAL_RUNTIME_EXTENSIONS =
+      ImmutableList.of(
+          CelExtensions.comprehensions(),
+          CelExtensions.encoders(OPTIONS),
+          CelExtensions.math(OPTIONS),
+          CelExtensions.sets(OPTIONS),
+          CelExtensions.strings(),
+          CelOptionalLibrary.INSTANCE);
+
   private static final CelParser PARSER_WITH_MACROS =
       CelParserFactory.standardCelParserBuilder()
           .setOptions(OPTIONS)
-          .addLibraries(
-              CelExtensions.bindings(),
-              CelExtensions.encoders(OPTIONS),
-              CelExtensions.math(OPTIONS),
-              CelExtensions.protos(),
-              CelExtensions.sets(OPTIONS),
-              CelExtensions.strings(),
-              CelOptionalLibrary.INSTANCE)
+          .addLibraries(CANONICAL_COMPILER_EXTENSIONS)
           .setStandardMacros(CelStandardMacro.STANDARD_MACROS)
           .build();
 
   private static final CelParser PARSER_WITHOUT_MACROS =
       CelParserFactory.standardCelParserBuilder()
           .setOptions(OPTIONS)
-          .addLibraries(
-              CelExtensions.bindings(),
-              CelExtensions.encoders(OPTIONS),
-              CelExtensions.math(OPTIONS),
-              CelExtensions.protos(),
-              CelExtensions.sets(OPTIONS),
-              CelExtensions.strings(),
-              CelOptionalLibrary.INSTANCE)
+          .addLibraries(CANONICAL_COMPILER_EXTENSIONS)
           .setStandardMacros()
           .build();
 
@@ -104,13 +112,7 @@ private static CelChecker getChecker(SimpleTest test) throws Exception {
         .setContainer(CelContainer.ofName(test.getContainer()))
         .addDeclarations(decls.build())
         .addFileTypes(dev.cel.expr.conformance.proto2.TestAllTypesExtensions.getDescriptor())
-        .addLibraries(
-            CelExtensions.bindings(),
-            CelExtensions.encoders(OPTIONS),
-            CelExtensions.math(OPTIONS),
-            CelExtensions.sets(OPTIONS),
-            CelExtensions.strings(),
-            CelOptionalLibrary.INSTANCE)
+        .addLibraries(CANONICAL_COMPILER_EXTENSIONS)
         .addMessageTypes(dev.cel.expr.conformance.proto2.TestAllTypes.getDescriptor())
         .addMessageTypes(dev.cel.expr.conformance.proto3.TestAllTypes.getDescriptor())
         .build();
@@ -119,12 +121,7 @@ private static CelChecker getChecker(SimpleTest test) throws Exception {
   private static final CelRuntime RUNTIME =
       CelRuntimeFactory.standardCelRuntimeBuilder()
           .setOptions(OPTIONS)
-          .addLibraries(
-              CelExtensions.encoders(OPTIONS),
-              CelExtensions.math(OPTIONS),
-              CelExtensions.sets(OPTIONS),
-              CelExtensions.strings(),
-              CelOptionalLibrary.INSTANCE)
+          .addLibraries(CANONICAL_RUNTIME_EXTENSIONS)
           .setExtensionRegistry(DEFAULT_EXTENSION_REGISTRY)
           .addMessageTypes(dev.cel.expr.conformance.proto2.TestAllTypes.getDescriptor())
           .addMessageTypes(dev.cel.expr.conformance.proto3.TestAllTypes.getDescriptor())

extensions/src/main/java/dev/cel/extensions/CelComprehensionsExtensions.java

@@ -159,6 +159,10 @@ public ImmutableSet<CelMacro> macros() {
             Operator.EXISTS_ONE.getFunction(),
             3,
             CelComprehensionsExtensions::expandExistsOneMacro),
+        CelMacro.newReceiverMacro(
+            Operator.EXISTS_ONE_NEW.getFunction(),
+            3,
+            CelComprehensionsExtensions::expandExistsOneMacro),
         CelMacro.newReceiverMacro(
             "transformList", 3, CelComprehensionsExtensions::transformListMacro),
         CelMacro.newReceiverMacro(

parser/src/main/java/dev/cel/parser/CelStandardMacro.java

@@ -54,6 +54,14 @@ public enum CelStandardMacro {
       CelMacro.newReceiverMacro(
           Operator.EXISTS_ONE.getFunction(), 2, CelStandardMacro::expandExistsOneMacro)),
 
+  /**
+   * Boolean comprehension which asserts that a predicate holds true for exactly one element in the
+   * input range.
+   */
+  EXISTS_ONE_NEW(
+      CelMacro.newReceiverMacro(
+          Operator.EXISTS_ONE_NEW.getFunction(), 2, CelStandardMacro::expandExistsOneMacro)),
+
   /**
    * Comprehension which applies a transform to each element in the input range and produces a list
    * of equivalent size as output.

parser/src/test/java/dev/cel/parser/CelParserImplTest.java

@@ -17,6 +17,7 @@
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertThrows;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.testing.junit.testparameterinjector.TestParameter;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import com.google.testing.junit.testparameterinjector.TestParameters;
@@ -260,10 +261,17 @@ public void parse_exprUnderMaxRecursionLimit_doesNotThrow(
   @TestParameters("{expression: 'A.all(a?b, c)'}")
   @TestParameters("{expression: 'A.exists(a?b, c)'}")
   @TestParameters("{expression: 'A.exists_one(a?b, c)'}")
+  @TestParameters("{expression: 'A.existsOne(a?b, c)'}")
   @TestParameters("{expression: 'A.filter(a?b, c)'}")
   public void parse_macroArgumentContainsSyntaxError_throws(String expression) {
     CelParser parser =
-        CelParserImpl.newBuilder().setStandardMacros(CelStandardMacro.STANDARD_MACROS).build();
+        CelParserImpl.newBuilder()
+            .setStandardMacros(
+                ImmutableSet.<CelStandardMacro>builder()
+                    .addAll(CelStandardMacro.STANDARD_MACROS)
+                    .add(CelStandardMacro.EXISTS_ONE_NEW)
+                    .build())
+            .build();
 
     CelValidationResult parseResult = parser.parse(expression);
 

parser/src/test/java/dev/cel/parser/CelParserParameterizedTest.java

@@ -26,6 +26,7 @@
 import com.google.auto.value.AutoValue;
 import com.google.common.base.Ascii;
 import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.annotations.Immutable;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.EnumDescriptor;
@@ -57,7 +58,11 @@
 public final class CelParserParameterizedTest extends BaselineTestCase {
   private static final CelParser PARSER =
       CelParserFactory.standardCelParserBuilder()
-          .setStandardMacros(CelStandardMacro.STANDARD_MACROS)
+          .setStandardMacros(
+              ImmutableSet.<CelStandardMacro>builder()
+                  .addAll(CelStandardMacro.STANDARD_MACROS)
+                  .add(CelStandardMacro.EXISTS_ONE_NEW)
+                  .build())
           .addLibraries(CelOptionalLibrary.INSTANCE)
           .addMacros(
               CelMacro.newGlobalVarArgMacro("noop_macro", (a, b, c) -> Optional.empty()),
@@ -162,6 +167,7 @@ public void parser() {
     runTest(PARSER, "aaa.bbb(ccc)");
     runTest(PARSER, "has(m.f)");
     runTest(PARSER, "m.exists_one(v, f)");
+    runTest(PARSER, "m.existsOne(v, f)");
     runTest(PARSER, "m.map(v, f)");
     runTest(PARSER, "m.map(v, p, f)");
     runTest(PARSER, "m.filter(v, p)");

parser/src/test/java/dev/cel/parser/CelStandardMacroTest.java

@@ -32,6 +32,8 @@ public void getFunction() {
     assertThat(CelStandardMacro.EXISTS.getFunction()).isEqualTo(Operator.EXISTS.getFunction());
     assertThat(CelStandardMacro.EXISTS_ONE.getFunction())
         .isEqualTo(Operator.EXISTS_ONE.getFunction());
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getFunction())
+        .isEqualTo(Operator.EXISTS_ONE_NEW.getFunction());
     assertThat(CelStandardMacro.FILTER.getFunction()).isEqualTo(Operator.FILTER.getFunction());
     assertThat(CelStandardMacro.MAP.getFunction()).isEqualTo(Operator.MAP.getFunction());
     assertThat(CelStandardMacro.MAP_FILTER.getFunction()).isEqualTo(Operator.MAP.getFunction());
@@ -90,6 +92,21 @@ public void testExistsOne() {
         .isEqualTo(CelStandardMacro.EXISTS_ONE.getDefinition().getKey().hashCode());
   }
 
+  @Test
+  public void testExistsOneNew() {
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getFunction())
+        .isEqualTo(Operator.EXISTS_ONE_NEW.getFunction());
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().getArgumentCount()).isEqualTo(2);
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().isReceiverStyle()).isTrue();
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().getKey())
+        .isEqualTo("existsOne:2:true");
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().isVariadic()).isFalse();
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().toString())
+        .isEqualTo(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().getKey());
+    assertThat(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().hashCode())
+        .isEqualTo(CelStandardMacro.EXISTS_ONE_NEW.getDefinition().getKey().hashCode());
+  }
+
   @Test
   public void testMap2() {
     assertThat(CelStandardMacro.MAP.getFunction()).isEqualTo(Operator.MAP.getFunction());

parser/src/test/resources/parser.baseline

@@ -784,6 +784,63 @@ M: m^#1:Expr.Ident#.exists_one(
   f^#4:Expr.Ident#
 )^#0:Expr.Call#
 
+I: m.existsOne(v, f)
+=====>
+P: __comprehension__(
+  // Variable
+  v,
+  // Target
+  m^#1:Expr.Ident#,
+  // Accumulator
+  @result,
+  // Init
+  0^#5:int64#,
+  // LoopCondition
+  true^#6:bool#,
+  // LoopStep
+  _?_:_(
+    f^#4:Expr.Ident#,
+    _+_(
+      @result^#7:Expr.Ident#,
+      1^#8:int64#
+    )^#9:Expr.Call#,
+    @result^#10:Expr.Ident#
+  )^#11:Expr.Call#,
+  // Result
+  _==_(
+    @result^#12:Expr.Ident#,
+    1^#13:int64#
+  )^#14:Expr.Call#)^#15:Expr.Comprehension#
+L: __comprehension__(
+  // Variable
+  v,
+  // Target
+  m^#1[1,0]#,
+  // Accumulator
+  @result,
+  // Init
+  0^#5[1,11]#,
+  // LoopCondition
+  true^#6[1,11]#,
+  // LoopStep
+  _?_:_(
+    f^#4[1,15]#,
+    _+_(
+      @result^#7[1,11]#,
+      1^#8[1,11]#
+    )^#9[1,11]#,
+    @result^#10[1,11]#
+  )^#11[1,11]#,
+  // Result
+  _==_(
+    @result^#12[1,11]#,
+    1^#13[1,11]#
+  )^#14[1,11]#)^#15[1,11]#
+M: m^#1:Expr.Ident#.existsOne(
+  v^#3:Expr.Ident#,
+  f^#4:Expr.Ident#
+)^#0:Expr.Call#
+
 I: m.map(v, f)
 =====>
 P: __comprehension__(