@bufbuild/cel
Version:
A CEL evaluator for ECMAScript
69 lines (68 loc) • 2.81 kB
JavaScript
;
// Copyright 2024-2025 Buf Technologies, Inc.
//
// 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.
Object.defineProperty(exports, "__esModule", { value: true });
exports.plan = plan;
const checked_pb_js_1 = require("@bufbuild/cel-spec/cel/expr/checked_pb.js");
const syntax_pb_js_1 = require("@bufbuild/cel-spec/cel/expr/syntax_pb.js");
const planner_js_1 = require("./planner.js");
const protobuf_1 = require("@bufbuild/protobuf");
const error_js_1 = require("./error.js");
const eval_js_1 = require("./eval.js");
const value_js_1 = require("./value.js");
const activation_js_1 = require("./activation.js");
const cache = new WeakMap();
/**
* Creates an execution plan for a CEL expression and returns a reusable evaluation function.
*
* Planning analyzes the expression structure once, independent of runtime variable values.
* The returned function can be called multiple times with different variable bindings.
*/
function plan(env, expr) {
// TODO(srikrsna): This can be avoided, if we refactor Planner into functions that use CelEnv directly.
let planner = cache.get(env);
if (planner === undefined) {
planner = new planner_js_1.Planner(env.dispatcher, env.registry, env.namespace);
cache.set(env, planner);
}
let maybeExpr;
if ((0, protobuf_1.isMessage)(expr, checked_pb_js_1.CheckedExprSchema)) {
maybeExpr = expr.expr;
}
else if ((0, protobuf_1.isMessage)(expr, syntax_pb_js_1.ParsedExprSchema)) {
maybeExpr = expr.expr;
}
else {
maybeExpr = expr;
}
const plan = planner.plan(maybeExpr ?? (0, protobuf_1.create)(syntax_pb_js_1.ExprSchema));
const withContext = (0, eval_js_1.withEvalContext)({ registry: env.registry }, {
id: plan.id,
eval(ctx) {
try {
let val = plan.eval(ctx);
if ((0, error_js_1.isCelError)(val)) {
return val;
}
return (0, value_js_1.unwrapAny)(val);
}
catch (ex) {
return (0, error_js_1.celError)(ex, plan.id);
}
},
});
return (ctx) => {
return withContext.eval(ctx !== undefined ? new activation_js_1.ObjectActivation(ctx) : activation_js_1.EMPTY_ACTIVATION);
};
}