validate-libsonnet

Type checking is a common grievance in the jsonnet eco-system, this library is an aid to validate function parameters and other values.

Here's a comprehensive example validating the function arguments against the arguments documented by docsonnet:

local d = import 'github.com/jsonnet-libs/docsonnet/doc-util/main.libsonnet';
local validate = import 'github.com/crdsonnet/validate-libsonnet/main.libsonnet';

{
  '#func'::
    d.func.new(
      'sample function',
      args=[
        d.arg('num', d.T.number),
        d.arg('str', d.T.string),
        d.arg('enum', d.T.string, enums=['valid', 'values']),
      ],
    ),
  func(num, str, enum)::
    assert validate.checkParamsFromDocstring(
      [num, str, enum],
      self['#func'],
    );
    {/* do something here */ },

  return: self.func(100, 'this is a string', 'valid'),
}

A failure output would look like this:

TRACE: vendor/github.com/crdsonnet/validate-libsonnet/main.libsonnet:63 
Invalid parameters:
  Parameter enum is invalid:
    Value "invalid" MUST match schema:
      {
        "enum": [
          "valid",
          "values"
        ],
        "type": "string"
      }
  Parameter str is invalid:
    Value 20 MUST match schema:
      {
        "type": "string"
      }
RUNTIME ERROR: Assertion failed
	fromdocstring.jsonnet:(15:5)-(19:31)	
	fromdocstring.jsonnet:21:11-40	object <anonymous>
	Field "return"	
	During manifestation	

Install

jb install github.com/crdsonnet/validate-libsonnet@master

Usage

local validate = import 'github.com/crdsonnet/validate-libsonnet/main.libsonnet'

Index

• fn checkParameters(checks)
• fn checkParamsFromDocstring(params, docstring)
• fn getChecksFromDocstring(params, docstring)
• fn schemaCheck(param, schema)

Fields

fn checkParameters

checkParameters(checks)

checkParameters validates parameters against their checks.

local validate = import 'github.com/crdsonnet/validate-libsonnet/main.libsonnet';

local func(arg) =
  assert validate.checkParameters({
    arg: std.isString(arg),
  });
  {/* do something here */ };

func('this is a string')

A failure output would look like this:

TRACE: vendor/github.com/crdsonnet/validate-libsonnet/main.libsonnet:63 
Invalid parameters:
  Parameter enum is invalid:
    Value "invalid" MUST match schema:
      {
        "enum": [
          "valid",
          "values"
        ],
        "type": "string"
      }
  Parameter str is invalid:
    Value 20 MUST match schema:
      {
        "type": "string"
      }
RUNTIME ERROR: Assertion failed
	fromdocstring.jsonnet:(15:5)-(19:31)	
	fromdocstring.jsonnet:21:11-40	object <anonymous>
	Field "return"	
	During manifestation	

fn checkParamsFromDocstring

checkParamsFromDocstring(params, docstring)

checkParamsFromDocstring validates params against a docsonnet docstring object.

local d = import 'github.com/jsonnet-libs/docsonnet/doc-util/main.libsonnet';
local validate = import 'github.com/crdsonnet/validate-libsonnet/main.libsonnet';

{
  '#func'::
    d.func.new(
      'sample function',
      args=[
        d.arg('num', d.T.number),
        d.arg('str', d.T.string),
        d.arg('enum', d.T.string, enums=['valid', 'values']),
      ],
    ),
  func(num, str, enum)::
    assert validate.checkParamsFromDocstring(
      [num, str, enum],
      self['#func'],
    );
    {/* do something here */ },

  return: self.func(100, 'this is a string', 'valid'),
}

A failure output would look like this:

TRACE: vendor/github.com/crdsonnet/validate-libsonnet/main.libsonnet:63 
Invalid parameters:
  Parameter enum is invalid:
    Value "invalid" MUST match schema:
      {
        "enum": [
          "valid",
          "values"
        ],
        "type": "string"
      }
  Parameter str is invalid:
    Value 20 MUST match schema:
      {
        "type": "string"
      }
RUNTIME ERROR: Assertion failed
	fromdocstring.jsonnet:(15:5)-(19:31)	
	fromdocstring.jsonnet:21:11-40	object <anonymous>
	Field "return"	
	During manifestation	

fn getChecksFromDocstring

getChecksFromDocstring(params, docstring)

getChecksFromDocstring returns checks for params derived from a docsonnet docstring object.

fn schemaCheck

schemaCheck(param, schema)

schemaCheck validates param against a JSON schema. Note that this function does not resolve "$ref" and recursion.