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Add code for Exercise 9 Codelabs
PiperOrigin-RevId: 632202746
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‎codelab/src/main/codelab/BUILD.bazel‎

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@@ -9,9 +9,12 @@ java_library(
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name = "codelab",
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srcs = glob(["*.java"]),
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deps = [
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"//bundle:cel", # unuseddeps: keep
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"//common", # unuseddeps: keep
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"//common:compiler_common", # unuseddeps: keep
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"//common:proto_json_adapter", # unuseddeps: keep
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"//common/ast", # unuseddeps: keep
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"//common/navigation", # unuseddeps: keep
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"//common/types", # unuseddeps: keep
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"//common/types:type_providers", # unuseddeps: keep
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"//compiler", # unuseddeps: keep
@@ -24,6 +27,7 @@ java_library(
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"//parser:macro", # unuseddeps: keep
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"//runtime", # unuseddeps: keep
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"//validator", # unuseddeps: keep
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"//validator:ast_validator", # unuseddeps: keep
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"//validator:validator_builder", # unuseddeps: keep
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"//validator/validators:duration", # unuseddeps: keep
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"//validator/validators:homogeneous_literal", # unuseddeps: keep

‎codelab/src/main/codelab/Exercise9.java‎

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// Copyright 2024 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package codelab;
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import com.google.rpc.context.AttributeContext;
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import dev.cel.common.CelAbstractSyntaxTree;
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import dev.cel.common.CelFunctionDecl;
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import dev.cel.common.CelOverloadDecl;
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import dev.cel.common.CelValidationException;
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import dev.cel.common.CelValidationResult;
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import dev.cel.common.types.SimpleType;
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import dev.cel.compiler.CelCompiler;
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import dev.cel.compiler.CelCompilerFactory;
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import dev.cel.parser.CelStandardMacro;
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import dev.cel.runtime.CelEvaluationException;
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import dev.cel.runtime.CelRuntime;
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import dev.cel.runtime.CelRuntimeFactory;
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import dev.cel.validator.CelValidator;
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import dev.cel.validator.CelValidatorFactory;
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/**
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* Exercise9 demonstrates how to author a custom AST validator to perform domain specific
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* validations.
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*
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* <p>Given a `google.rpc.context.AttributeContext.Request` message, validate that its fields follow
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* the expected HTTP specification.
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*
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* <p>Given an expression containing an expensive function call, validate that it is not nested
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* within a macro.
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*/
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final class Exercise9 {
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private static final CelCompiler CEL_COMPILER =
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CelCompilerFactory.standardCelCompilerBuilder()
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.setStandardMacros(CelStandardMacro.ALL)
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.addFunctionDeclarations(
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CelFunctionDecl.newFunctionDeclaration(
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"is_prime_number",
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CelOverloadDecl.newGlobalOverload(
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"is_prime_number_int",
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"Invokes an expensive RPC call to check if the value is a prime number.",
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SimpleType.BOOL,
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SimpleType.INT)))
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.addMessageTypes(AttributeContext.Request.getDescriptor())
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.build();
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private static final CelRuntime CEL_RUNTIME =
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CelRuntimeFactory.standardCelRuntimeBuilder()
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.addMessageTypes(AttributeContext.Request.getDescriptor())
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.build();
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private static final CelValidator CEL_VALIDATOR =
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CelValidatorFactory.standardCelValidatorBuilder(CEL_COMPILER, CEL_RUNTIME)
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// Add your custom AST validators here
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.build();
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/**
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* Compiles the input expression.
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*
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* @throws CelValidationException If the expression contains parsing or type-checking errors.
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*/
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CelAbstractSyntaxTree compile(String expression) throws CelValidationException {
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return CEL_COMPILER.compile(expression).getAst();
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}
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/** Validates a type-checked AST. */
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CelValidationResult validate(CelAbstractSyntaxTree checkedAst) {
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return CEL_VALIDATOR.validate(checkedAst);
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}
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/** Evaluates the compiled AST. */
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Object eval(CelAbstractSyntaxTree ast) throws CelEvaluationException {
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return CEL_RUNTIME.createProgram(ast).eval();
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}
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/**
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* Performs general validation on AttributeContext.Request message. The validator raises errors if
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* the HTTP request is malformed and semantically invalid (e.g: contains disallowed HTTP methods).
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* Warnings are presented if there's potential problems with the contents of the request (e.g:
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* using "http" instead of "https" for scheme).
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*/
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static final class AttributeContextRequestValidator {
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// Implement validate method here
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}
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/** Prevents nesting an expensive function call within a macro. */
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static final class ComprehensionSafetyValidator {
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// Implement validate method here
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}
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}

‎codelab/src/main/codelab/solutions/BUILD.bazel‎

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@@ -9,9 +9,12 @@ java_library(
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name = "solutions",
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srcs = glob(["*.java"]),
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deps = [
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"//bundle:cel",
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"//common",
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"//common:compiler_common",
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"//common:proto_json_adapter",
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"//common/ast",
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"//common/navigation",
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"//common/types",
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"//common/types:type_providers",
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"//compiler",
@@ -24,6 +27,7 @@ java_library(
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"//parser:macro",
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"//runtime",
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"//validator",
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"//validator:ast_validator",
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"//validator:validator_builder",
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"//validator/validators:duration",
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"//validator/validators:homogeneous_literal",

‎codelab/src/main/codelab/solutions/Exercise9.java‎

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// Copyright 2024 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package codelab.solutions;
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import com.google.common.collect.ImmutableSet;
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import com.google.rpc.context.AttributeContext;
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import dev.cel.bundle.Cel;
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import dev.cel.common.CelAbstractSyntaxTree;
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import dev.cel.common.CelFunctionDecl;
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import dev.cel.common.CelOverloadDecl;
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import dev.cel.common.CelValidationException;
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import dev.cel.common.CelValidationResult;
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import dev.cel.common.ast.CelExpr;
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import dev.cel.common.ast.CelExpr.CelStruct;
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import dev.cel.common.ast.CelExpr.ExprKind.Kind;
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import dev.cel.common.navigation.CelNavigableAst;
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import dev.cel.common.types.SimpleType;
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import dev.cel.compiler.CelCompiler;
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import dev.cel.compiler.CelCompilerFactory;
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import dev.cel.parser.CelStandardMacro;
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import dev.cel.runtime.CelEvaluationException;
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import dev.cel.runtime.CelRuntime;
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import dev.cel.runtime.CelRuntimeFactory;
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import dev.cel.validator.CelAstValidator;
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import dev.cel.validator.CelValidator;
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import dev.cel.validator.CelValidatorFactory;
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/**
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* Exercise9 demonstrates how to author a custom AST validator to perform domain specific
42+
* validations.
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*
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* <p>Given a `google.rpc.context.AttributeContext.Request` message, validate that its fields follow
45+
* the expected HTTP specification.
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*
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* <p>Given an expression containing an expensive function call, validate that it is not nested
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* within a macro.
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*/
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final class Exercise9 {
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private static final CelCompiler CEL_COMPILER =
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CelCompilerFactory.standardCelCompilerBuilder()
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.setStandardMacros(CelStandardMacro.ALL)
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.addFunctionDeclarations(
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CelFunctionDecl.newFunctionDeclaration(
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"is_prime_number",
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CelOverloadDecl.newGlobalOverload(
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"is_prime_number_int",
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"Invokes an expensive RPC call to check if the value is a prime number.",
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SimpleType.BOOL,
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SimpleType.INT)))
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.addMessageTypes(AttributeContext.Request.getDescriptor())
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.build();
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private static final CelRuntime CEL_RUNTIME =
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CelRuntimeFactory.standardCelRuntimeBuilder()
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.addMessageTypes(AttributeContext.Request.getDescriptor())
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.build();
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private static final CelValidator CEL_VALIDATOR =
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CelValidatorFactory.standardCelValidatorBuilder(CEL_COMPILER, CEL_RUNTIME)
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.addAstValidators(
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new AttributeContextRequestValidator(), //
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new ComprehensionSafetyValidator())
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.build();
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/**
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* Compiles the input expression.
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*
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* @throws CelValidationException If the expression contains parsing or type-checking errors.
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*/
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CelAbstractSyntaxTree compile(String expression) throws CelValidationException {
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return CEL_COMPILER.compile(expression).getAst();
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}
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/** Validates a type-checked AST. */
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CelValidationResult validate(CelAbstractSyntaxTree checkedAst) {
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return CEL_VALIDATOR.validate(checkedAst);
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}
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/** Evaluates the compiled AST. */
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Object eval(CelAbstractSyntaxTree ast) throws CelEvaluationException {
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return CEL_RUNTIME.createProgram(ast).eval();
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}
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/**
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* Performs general validation on AttributeContext.Request message. The validator raises errors if
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* the HTTP request is malformed and semantically invalid (e.g: contains disallowed HTTP methods).
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* Warnings are presented if there's potential problems with the contents of the request (e.g:
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* using "http" instead of "https" for scheme).
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*/
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static final class AttributeContextRequestValidator implements CelAstValidator {
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private static final ImmutableSet<String> ALLOWED_HTTP_METHODS =
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ImmutableSet.of("GET", "POST", "PUT", "DELETE");
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@Override
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public void validate(CelNavigableAst navigableAst, Cel cel, IssuesFactory issuesFactory) {
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navigableAst
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.getRoot()
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.allNodes()
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.filter(node -> node.getKind().equals(Kind.STRUCT))
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.map(node -> node.expr().struct())
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.filter(
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struct -> struct.messageName().equals("google.rpc.context.AttributeContext.Request"))
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.forEach(
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struct -> {
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for (CelStruct.Entry entry : struct.entries()) {
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String fieldKey = entry.fieldKey();
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if (fieldKey.equals("method")) {
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String entryStringValue = getStringValue(entry.value());
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if (!ALLOWED_HTTP_METHODS.contains(entryStringValue)) {
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issuesFactory.addError(
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entry.value().id(), entryStringValue + " is not an allowed HTTP method.");
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}
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} else if (fieldKey.equals("scheme")) {
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String entryStringValue = getStringValue(entry.value());
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if (!entryStringValue.equals("https")) {
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issuesFactory.addWarning(
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entry.value().id(), "Prefer using https for safety.");
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}
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}
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}
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});
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}
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/**
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* Reads the underlying string value from the expression.
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*
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* @throws UnsupportedOperationException if the expression is not a constant string value.
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*/
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private static String getStringValue(CelExpr celExpr) {
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return celExpr.constant().stringValue();
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}
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}
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/** Prevents nesting an expensive function call within a macro. */
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static final class ComprehensionSafetyValidator implements CelAstValidator {
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private static final String EXPENSIVE_FUNCTION_NAME = "is_prime_number";
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@Override
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public void validate(CelNavigableAst navigableAst, Cel cel, IssuesFactory issuesFactory) {
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navigableAst
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.getRoot()
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.allNodes()
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.filter(node -> node.getKind().equals(Kind.COMPREHENSION))
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.forEach(
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comprehensionNode -> {
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boolean isFunctionWithinMacro =
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comprehensionNode
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.descendants()
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.anyMatch(
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node ->
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node.expr()
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.callOrDefault()
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.function()
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.equals(EXPENSIVE_FUNCTION_NAME));
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if (isFunctionWithinMacro) {
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issuesFactory.addError(
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comprehensionNode.id(),
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EXPENSIVE_FUNCTION_NAME + " function cannot be used within CEL macros.");
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}
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});
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}
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}
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}

‎codelab/src/test/codelab/BUILD.bazel‎

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],
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)
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java_test(
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name = "Exercise9Test",
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srcs = ["Exercise9Test.java"],
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tags = ["notap"],
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test_class = "codelab.Exercise9Test",
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deps = [
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"//:java_truth",
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"//codelab",
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"//common",
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"//common:compiler_common",
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"@maven//:com_google_api_grpc_proto_google_common_protos",
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"@maven//:com_google_testparameterinjector_test_parameter_injector",
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"@maven//:junit_junit",
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],
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)
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test_suite(
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name = "exercise_test_suite",
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tags = ["notap"],

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