A command-line JSON and YAML validator that's on your wavelength


Keywords
JSON, YAML, schema, validator, validation, jsonschema, json-schema, command-line
License
MIT
Install
npm install v8r@0.10.1

Documentation

v8r

build coverage version license node

A command-line JSON and YAML validator that's on your wavelength.

Getting Started

One-off:

npx v8r@latest <filename>

Local install:

npm install -g v8r
v8r <filename>

Usage Examples

Validating files

v8r can validate JSON or YAML files. You can pass filenames or glob patterns:

# single filename
$ v8r package.json

# multiple files
$ v8r file1.json file2.json

# glob patterns
$ v8r 'dir/*.yml' 'dir/*.yaml'

DigitalOcean's Glob Tool can be used to help construct glob patterns

Manually specifying a schema

By default, v8r queries Schema Store to detect a suitable schema based on the filename.

# if v8r can't auto-detect a schema for your file..
$ v8r feature.geojson
✖ Could not find a schema to validate feature.geojson

# ..you can specify one using the --schema flag
$ v8r feature.geojson --schema https://json.schemastore.org/geojson
ℹ Validating feature.geojson against schema from https://json.schemastore.org/geojson ...
✔ feature.geojson is valid

Using a custom catlog

Using the --schema flag will validate all files matched by the glob pattern against that schema. You can also define a custom schema catalog. v8r will search any custom catalogs before falling back to Schema Store.

$ cat > my-catalog.json <<EOF
{ "\$schema": "https://json.schemastore.org/schema-catalog.json",
  "version": 1,
  "schemas": [ { "name": "geojson",
                 "description": "geojson",
                 "url": "https://json.schemastore.org/geojson.json",
                 "fileMatch": ["*.geojson"] } ] }
EOF

$ v8r feature.geojson -c my-catalog.json
ℹ Found schema in my-catalog.json ...
ℹ Validating feature.geojson against schema from https://json.schemastore.org/geojson ...
✔ feature.geojson is valid

This can be used to specify different custom schemas for multiple file patterns.

Exit codes

  • v8r always exits with code 0 when:

    • The input glob pattern(s) matched one or more files, all input files were validated against a schema, and all input files were valid
    • v8r was called with --help or --version flags
  • By default v8r exits with code 1 when an error was encountered trying to validate one or more input files. For example:

    • No suitable schema could be found
    • An error was encountered during an HTTP request
    • An input file was not JSON or yaml
    • etc

    This behaviour can be modified using the --ignore-errors flag. When invoked with --ignore-errors v8r will exit with code 0 even if one of these errors was encountered while attempting validation. A non-zero exit code will only be issued if validation could be completed successfully and the file was invalid.

  • v8r always exits with code 98 when:

    • An input glob pattern was invalid
    • An input glob pattern was valid but did not match any files
  • v8r always exits with code 99 when:

    • The input glob pattern matched one or more files, one or more input files were validated against a schema and the input file was invalid

FAQ

How does v8r decide what schema to validate against if I don't supply one?

💡 v8r queries the Schema Store catalog to try and find a suitable schema based on the name of the input file.

My file is valid, but it doesn't validate against one of the suggested schemas.

💡 v8r is a fairly thin layer of glue between Schema Store (where the schemas come from) and ajv (the validation engine). It is likely that this kind of problem is either an issue with the schema or validation engine.

What JSON schema versions are supported?

💡 v8r works with JSON schema drafts:

  • draft-04
  • draft-06
  • draft-07
  • draft 2019-09
  • draft 2020-12

Will 100% of the schemas on schemastore.org work with this tool?

💡 No. There are some with known issues

Can v8r validate against a local schema?

💡 Yes. The --schema flag can be either a path to a local file or a URL.