@bufbuild/cel

This package provides a CEL evaluator for ECMAScript.

Example

Let's evaluate a CEL expression that has the variable name and uses the strings extension functions:

import { run } from "@bufbuild/cel";
import { strings } from "@bufbuild/cel/ext";

run(
  `name.indexOf('taco') == 0`,
  {name: "tacocat"},
  {funcs: STRINGS_EXT_FUNCS },
); // true

That's it!

For an example of creating resusable evaluator and more, refer to the example.ts.

Types

The table below maps JS types to CEL types.

• Input column is any value that can be passed to the evaluator as input. (CelInput)
• CEL Type column is the CEL type it will represent at runtime. (CelType)
• Output column is the type of values that are returned by the evaluator, either as returned from eval or as arguments to function implementations. (CelValue)

| Input (JS Type) | CEL Type (runtime) | Output (JS Type) | | --- | --- | --- | | number, {Float,Double}Value | double | number | | bigint, all signed int wrappers | int | bigint | | CelUint, all unsigned int wrappers | uint | CelUint | | string, StringValue | string | string | | Uint8Array, BytesValue | bytes | Uint8Array | | Map, ReflectMap | map | CelMap | | any[], ReflectList | list | CelList | | boolean, BoolValue | bool | boolean | | null | null_type | null | | CelType | type | CelType | | Timestamp, ReflectMessage | timestamp | ReflectMessage | | Duration, ReflectMessage | duration | ReflectMessage | | Message, ReflectMessage, Any | <typeName> | ReflectMessage | | google.protobuf.Value and friends | double/bool/string/list/map/null | number/boolean/string/CelList/CelMap |