@asyncapi/avro-schema-parser
v3.0.24
Published
An AsyncAPI schema parser for Avro 1.x schemas.
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Avro Schema Parser
An AsyncAPI schema parser for Avro 1.x schemas.
Note Version >=
2.0.0
of this package is only supported by the@asyncapi/parser
version >=2.0.0
.
Installation
npm install @asyncapi/avro-schema-parser
// OR
yarn add @asyncapi/avro-schema-parser
Usage
import { Parser } from '@asyncapi/parser';
import { AvroSchemaParser } from '@asyncapi/avro-schema-parser';
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload: # The following is an Avro schema in YAML format (JSON format is also supported)
type: record
name: User
namespace: com.company
doc: User information
fields:
- name: displayName
type: string
- name: email
type: string
- name: age
type: int
`
const { document } = await parser.parse(asyncapiWithAvro);
const { Parser } = require('@asyncapi/parser');
const { AvroSchemaParser } = require('@asyncapi/raml-dt-schema-parser');
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload: # The following is an Avro schema in YAML format (JSON format is also supported)
type: record
name: User
namespace: com.company
doc: User information
fields:
- name: displayName
type: string
- name: email
type: string
- name: age
type: int
Usage with remote references
import { Parser } from '@asyncapi/parser';
import { AvroSchemaParser } from '@asyncapi/avro-schema-parser';
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'https://schemas.example.com/user'
`
const { document } = await parser.parse(asyncapiWithAvro);
const { Parser } = require('@asyncapi/parser');
const { AvroSchemaParser } = require('@asyncapi/raml-dt-schema-parser');
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'https://schemas.example.com/user'
`
const { document } = await parser.parse(asyncapiWithAvro);
Usage with local references
import { Parser } from '@asyncapi/parser';
import { AvroSchemaParser } from '@asyncapi/avro-schema-parser';
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'local/path/to/file/user'
`
const { document } = await parser.parse(asyncapiWithAvro);
const { Parser } = require('@asyncapi/parser');
const { AvroSchemaParser } = require('@asyncapi/raml-dt-schema-parser');
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'local/path/to/file/user'
`
const { document } = await parser.parse(asyncapiWithAvro);
Usage with Confluent Schema Registry
Create an API key
Copy the key and the secret
Use them on your AsyncAPI document
import { Parser } from '@asyncapi/parser';
import { AvroSchemaParser } from '@asyncapi/avro-schema-parser';
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'https://LY422RBU2HN6JQ5T:+f8wz9a0iM06AX7xfwbzSM9YPw/JIkr22Cvl5EKT5Hb1d/nz5nOpbXV/[email protected]/subjects/test/versions/1/schema'
`
const { document } = await parser.parse(asyncapiWithAvro);
const { Parser } = require('@asyncapi/parser');
const { AvroSchemaParser } = require('@asyncapi/raml-dt-schema-parser');
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
$ref: 'https://LY422RBU2HN6JQ5T:+f8wz9a0iM06AX7xfwbzSM9YPw/JIkr22Cvl5EKT5Hb1d/nz5nOpbXV/[email protected]/subjects/test/versions/1/schema'
`
const { document } = await parser.parse(asyncapiWithAvro);
Features
Validation of Avro schemas
Avro schemas included in parsed AsyncAPI documents are validated using avsc. The parser.validate(...)
function returns all validation issues.
import { Parser } from '@asyncapi/parser';
import { AvroSchemaParser } from '@asyncapi/avro-schema-parser';
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithInvalidAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
type: notAValidAvroType
`;
const diagnostics = await parser.validate(doc);
// Custom schema issues are stored by the code "asyncapi-schemas-v2"
const avroDiagnostics = diagnostics.filter(d => d.code === 'asyncapi-schemas-v2');
console.log(avroDiagnostics);
const { Parser } = require('@asyncapi/parser');
const { AvroSchemaParser } = require('@asyncapi/raml-dt-schema-parser');
const parser = new Parser();
parser.registerSchemaParser(AvroSchemaParser());
const asyncapiWithInvalidAvro = `
asyncapi: 2.0.0
info:
title: Example with Avro
version: 0.1.0
channels:
example:
publish:
message:
schemaFormat: 'application/vnd.apache.avro;version=1.9.0'
payload:
type: notAValidAvroType
`;
const diagnostics = await parser.validate(doc);
// Custom schema issues are stored by the code "asyncapi-schemas-v2"
const avroDiagnostics = diagnostics.filter(d => d.code === 'asyncapi-schemas-v2');
console.log(avroDiagnostics);
Note
parser.parse(...)
function also returnsdiagnostics
data with all the validation issues.
Support of required attributes
Required fields are fields with no default value and without the "null"
union element.
Support for extra attributes on top of Avro specification
Additional attributes not defined in the Avro Specification are permitted and are treated as a metadata by the specification. To improve human readability of generated AsyncAPI documentation and to leverage more features from the JSON schema we included support for the extra attributes that can be added into Avro document.
List of all supported extra attributes
example
- Can be used to define the example value from the business domain of given field. Value will be propagated into examples attribute of JSON schema and therefore will be picked for the generated "Example of payload" when using some AsyncAPI documentation generator.
For Number instances:
multipleOf
- Can be used to define the multipleOf value of a numeric instance. ThemultipleOf
MUST be a number, strictly greater than 0.maximum
- Can be used to define the maximum value of a numeric instance.exclusiveMaximum
- Can be used to define the exclusiveMaximum value of a numeric instance.minimum
- Can be used to define the minimum value of a numeric instance.exclusiveMinimum
- Can be used to define the exclusiveMinimum value of a numeric instance.
For String instances:
maxLength
- Can be used to define the maxLength value of a string instance. The value of this keyword MUST be a non-negative integer.minLength
- Can be used to define the minLength value of a string instance. The value of this keyword MUST be a non-negative integer.pattern
- Can be used to define the pattern value of a string instance.
For Array instances:
maxItems
- Can be used to define the maxItems value of a string instance. The value of this keyword MUST be a non-negative integer.minItems
- Can be used to define the minItems value of a string instance. The value of this keyword MUST be a non-negative integer.uniqueItems
- Can be used to define the uniqueItems value of a string instance. The value of this keyword MUST be a boolean.
Support for names and namespaces
If, at the top level of the Avro schema, the 'name' attribute is defined, it will be copied to the corresponding JSON schema's 'x-parser-schema-id' attribute. If the Avro schema also has the 'namespace' attribute defined, then that schema's fully qualified name will be put into that attribute. The fully qualified name is defined by the namespace, followed by a dot, followed by the name.
If there are two schemas that resolve to the same fully qualified name, only the last one will be returned by the parser. Make sure names of your schemas are unique.
If no name attribute is present, the 'x-parser-schema-id' will have a generated unique id with a name like 'anonymous-schema-1' generated by the main parser. 'x-parser-schema-id' is one of the custom extensions supported by the parser.
Limitations
Float and double-precision numbers
JSON numbers (RFC 4627, section 2.4) don't define any limit to the scale and/or precision of numbers. That said, we can enforce limits on int
and long
but we can't enforce them on float
and double
because they can't accurately be represented on JSON Schema.
Since we support extra attributes on field, you can set
minimum
andmaximum
attribute on float and double types to display number limits.
Hardcoded key and secret
This is not a limitation of this package per se but of the JSON Reference RFC. So far, you can only hardcode the values for key
and secret
on the $ref
URL.
Contributors
Thanks goes to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome!