@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:

``ts
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.

$3

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 | \ | ReflectMessage |
| google.protobuf.Value and friends | double/bool/string/list/map/null | number/boolean/string/CelList/CelMap |