gem-hunter

Command line interface for ajv, one of the fastest json schema validators. Supports JSON, JSON5, and YAML.

• Installation
• JSON schema version
• Commands
  • Help
  • Validate data
  • Compile schemas
  • Migrate schemas
  • Test validation result
• Ajv options
• Version History, License

npm install -g ajv-cli

Parameter --spec can be used with all commands (other than help) to choose JSON schema language:

• --spec=draft7 (default) - support JSON Schema draft-07 (uses import Ajv from "ajv")
• --spec=draft2019 - support JSON Schema draft-2019-09 (uses import Ajv from "ajv/dist/2019")
• --spec=draft2020 - support JSON Schema draft-2020-12 (uses import Ajv from "ajv/dist/2020")
• --spec=jtd - support JSON Type Definition (uses import Ajv from "ajv/dist/jtd")

ajv help
ajv help validate
ajv help compile
ajv help migrate
ajv help test

This command validates data files against JSON-schema

ajv validate -s test/schema.json -d test/valid_data.json
ajv -s test/schema.json -d test/valid_data.json

You can omit validate command name and .json from the input file names.

Only one schema can be passed in this parameter

Multiple data files can be passed, as in -r parameter:

ajv -s test/schema.json -d "test/valid*.json"

If some file is invalid exit code will be 1.

The schema in -s parameter can reference any of these schemas with $ref keyword.

Multiple schemas can be passed both by using this parameter multiple times and with glob patterns. Glob pattern should be quoted and extensions cannot be omitted.

Schemas can use any of these schemas as a meta-schema (that is the schema used in $schema keyword - it is used to validate the schema itself).

Multiple meta-schemas can be passed, as in -r parameter.

You can pass module(s) that define custom keywords/formats. The modules should export a function that accepts Ajv instance as a parameter. The file name should start with ".", it will be resolved relative to the current folder. The package name can also be passed - it will be used in require as is. These modules can be written in TypeScript if you have ts-node installed.

For example, you can use -c ajv-keywords to add all keywords from ajv-keywords package or -c ajv-keywords/keywords/typeof to add only typeof keyword.

• --errors=: error reporting format. Possible values:

  • js (default): JavaScript object
  • json: JSON with indentation and line-breaks
  • line: JSON without indentation/line-breaks (for easy parsing)
  • text: human readable error messages with data paths

• --changes=: detect changes in data after validation.
  Data can be modified with Ajv options --remove-additional, --use-defaults and --coerce-types).
  The changes are reported in JSON-patch format (RFC6902).
  Possible values are js (default), json and line (see --errors option).

This command validates and compiles schema without validating any data.

It can be used to check that the schema is valid and to create a standalone module exporting validation function(s).

ajv compile -s schema

# compile to module file
ajv compile -s schema -o validate.js

## compile to stdout, to allow code formatting (js-beautify has to be installed separately)
ajv compile -s schema -o | js-beautify > validate.js

Multiple schemas can be passed both by using this parameter multiple times and with glob patterns.

ajv compile -s "test/schema*.json"

If multiple schemas are compiled with this option the module will have multiple exports named as schema $id's or as file names, otherwise the module will export validation function as default export.

ajv compile -s "schema.json" -o "validate_schema.js"

-o without parameter should be used to output code to stdout to pass it to some code formatter.

This command also supports parameters -r, -m and -c as in validate command.

This command validates and migrates schema from JSON Schema draft-04 to draft-07, draft-2019-09 or draft-2020-12 using json-schema-migrate package.

The version of JSON Schema is determined by --spec parameter (only "draft7", "draft2019" or "draft2020").

ajv migrate -s schema

# compile to specific file name
ajv migrate -s schema -o migrated_schema.json

Multiple schemas can be passed both by using this parameter multiple times and with glob patterns.

ajv migrate -s "test/schema*.json"

If parameter -o is not specified the migrated schema is written to the same file and the original file is preserved with .bak extension.

If migration doesn't change anything in the schema file no changes in files are made.

Only a single schema can be migrated with this option.

ajv compile -s "schema.json" -o migrated_schema.json

• --indent=: indentation in migrated schema JSON file, 4 by default
• --validate-schema=false: skip schema validation

This command asserts that the result of the validation is as expected.

ajv test -s test/schema.json -d test/valid_data.json --valid
ajv test -s test/schema.json -d test/invalid_data.json --invalid

If the option --valid (--invalid) is used for the test to pass (exit code 0) the data file(s) should be valid (invalid).

This command supports the same options and parameters as validate with the exception of --changes.

You can pass the following Ajv options:

Options can be passed using either dash-case or camelCase.

See Ajv Options for more information.

See https://github.com/ajv-validator/ajv-cli/releases

MIT