Compile JSONSchema to TypeScript Type Declarations

json-schema-to-typescript

Compile json schema to typescript typings

Example

Input:

{
  "title": "Example Schema",
  "type": "object",
  "properties": {
    "firstName": {
      "type": "string"
    },
    "lastName": {
      "type": "string"
    },
    "age": {
      "description": "Age in years",
      "type": "integer",
      "minimum": 0
    },
    "hairColor": {
      "enum": ["black", "brown", "blue"],
      "type": "string"
    }
  },
  "additionalProperties": false,
  "required": ["firstName", "lastName"]
}

Output:

export interface ExampleSchema {
  firstName: string;
  lastName: string;
  /**
   * Age in years
   */
  age?: number;
  hairColor?: "black" | "brown" | "blue";
}

Installation

# Using Yarn:
yarn add json-schema-to-typescript

# Or, using NPM:
npm install json-schema-to-typescript --save

Usage

import { compile, compileFromFile } from 'json-schema-to-typescript'

// compile from file
compileFromFile('foo.json')
  .then(ts => fs.writeFileSync('foo.d.ts', ts))

// or, compile a JS object
let mySchema = {
  properties: [...]
}
compile(mySchema, 'MySchema')
  .then(ts => ...)

See server demo and browser demo for full examples.

Options

compileFromFile and compile accept options as their last argument (all keys are optional):

key	type	default	description
additionalProperties	boolean	`true`	Default value for `additionalProperties`, when it is not explicitly set
bannerComment	string	`"/* eslint-disable /\n/\n This file was automatically generated by json-schema-to-typescript.\n* DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,\n* and run json-schema-to-typescript to regenerate this file.\n*/"`	Disclaimer comment prepended to the top of each generated file
cwd	string	`process.cwd()`	Root directory for resolving `$ref`s
declareExternallyReferenced	boolean	`true`	Declare external schemas referenced via `$ref`?
enableConstEnums	boolean	`true`	Prepend enums with `const`?
format	boolean	`true`	Format code? Set this to `false` to improve performance.
ignoreMinAndMaxItems	boolean	`false`	Ignore maxItems and minItems for `array` types, preventing tuples being generated.
maxItems	number	`20`	Maximum number of unioned tuples to emit when representing bounded-size array types, before falling back to emitting unbounded arrays. Increase this to improve precision of emitted types, decrease it to improve performance, or set it to `-1` to ignore `maxItems`.
style	object	`{ bracketSpacing: false, printWidth: 120, semi: true, singleQuote: false, tabWidth: 2, trailingComma: 'none', useTabs: false }`	A Prettier configuration
unknownAny	boolean	`true`	Use `unknown` instead of `any` where possible
unreachableDefinitions	boolean	`false`	Generates code for `$defs` that aren't referenced by the schema.
strictIndexSignatures	boolean	`false`	Append all index signatures with `\| undefined` so that they are strictly typed.
$refOptions	object	`{}`	$RefParser Options, used when resolving `$ref`s

CLI

A CLI utility is provided with this package.

cat foo.json | json2ts > foo.d.ts
# or
json2ts foo.json > foo.d.ts
# or
json2ts foo.json foo.d.ts
# or
json2ts --input foo.json --output foo.d.ts
# or
json2ts -i foo.json -o foo.d.ts
# or (quote globs so that your shell doesn't expand them)
json2ts -i 'schemas/**/*.json'
# or
json2ts -i schemas/ -o types/

You can pass any of the options described above (including style options) as CLI flags. Boolean values can be set to false using the no- prefix.

# generate code for definitions that aren't referenced
json2ts -i foo.json -o foo.d.ts --unreachableDefinitions
# use single quotes and disable trailing semicolons
json2ts -i foo.json -o foo.d.ts --style.singleQuote --no-style.semi

Tests

npm test

Features

title => interface
Primitive types:
- array
- homogeneous array
- boolean
- integer
- number
- null
- object
- string
- homogeneous enum
- heterogeneous enum
Non/extensible interfaces
Custom JSON-schema extensions
Nested properties
Schema definitions
Schema references
Local (filesystem) schema references
External (network) schema references
Add support for running in browser
default interface name
infer unnamed interface name from filename
allOf ("intersection")
anyOf ("union")
oneOf (treated like anyOf)
maxItems (eg)
minItems (eg)
additionalProperties of type
patternProperties (partial support)
extends
required properties on objects (eg)
validateRequired (eg)
literal objects in enum (eg)
referencing schema by id (eg)
custom typescript types via tsType

Custom schema properties:

tsType: Overrides the type that's generated from the schema. Useful for forcing a type to any or when using non-standard JSON schema extensions (eg).
tsEnumNames: Overrides the names used for the elements in an enum. Can also be used to create string enums (eg).

Not expressible in TypeScript:

dependencies (single, multiple)
divisibleBy (eg)
format (eg)
multipleOf (eg)
maximum (eg)
minimum (eg)
maxProperties (eg)
minProperties (eg)
not/disallow
oneOf ("xor", use anyOf instead)
pattern (string, regex)
uniqueItems (eg)

FAQ

JSON-Schema-to-TypeScript is crashing on my giant file. What can I do?

Prettier is known to run slowly on really big files. To skip formatting and improve performance, set the format option to false.

Who uses JSON-Schema-to-TypeScript?

Download Details:

Author: Bcherny
Source Code: https://github.com/bcherny/json-schema-to-typescript

#typescript #json #schema

The Definitive Guide to TypeScript & Possibly The Best TypeScript Book

TypeScript Deep Dive

I've been looking at the issues that turn up commonly when people start using TypeScript. This is based on the lessons from Stack Overflow / DefinitelyTyped and general engagement with the TypeScript community. You can follow for updates and don't forget to ★ on GitHub 🌹

Reviews

Thanks for the wonderful book. Learned a lot from it. (link)
Its probably the Best TypeScript book out there. Good Job (link)
Love how precise and clear the examples and explanations are! (link)
For the low, low price of free, you get pages of pure awesomeness. Chock full of source code examples and clear, concise explanations, TypeScript Deep Dive will help you learn TypeScript development. (link)
Just a big thank you! Best TypeScript 2 detailed explanation! (link)
This gitbook got my project going pronto. Fluent easy read 5 stars. (link)
I recommend the online #typescript book by @basarat you'll love it.(link)
I've always found this by @basarat really helpful. (link)
We must highlight TypeScript Deep Dive, an open source book.(link)
Great online resource for learning. (link)
Thank you for putting this book together, and for all your hard work within the TypeScript community. (link)
TypeScript Deep Dive is one of the best technical texts I've read in a while. (link)
Thanks @basarat for the TypeScript Deep Dive Book. Help me a lot with my first TypeScript project. (link)
Thanks to @basarat for this great #typescript learning resource. (link)
Guyz excellent book on Typescript(@typescriptlang) by @basarat (link)
Leaning on the legendary @basarat's "TypeScript Deep Dive" book heavily at the moment (link)
numTimesPointedPeopleToBasaratsTypeScriptBook++; (link)
A book not only for typescript, a good one for deeper JavaScript knowledge as well. link
In my new job, we're using @typescriptlang, which I am new to. This is insanely helpful huge thanks, @basarat! link
Thank you for writing TypeScript Deep Dive. I have learned so much. link
Loving @basarat's @typescriptlang online book basarat.gitbooks.io/typescript/# loaded with great recipes! link
Microsoft doc is great already, but if want to "dig deeper" into TypeScript I find this book of great value link
Thanks, this is a great book 🤓🤓 link
Deep dive to typescript is awesome in so many levels. i find it very insightful. Thanks link
@basarat's intro to @typescriptlang is still one of the best going (if not THE best) link
This is sweet! So many #typescript goodies! link

Get Started

If you are here to read the book online get started.

Translations

Book is completely free so you can copy paste whatever you want without requiring permission. If you have a translation you want me to link here. Send a PR.

Other Options

You can also download one of the Epub, Mobi, or PDF formats from the actions tab by clicking on the latest build run. You will find the files in the artifacts section.

Special Thanks

All the amazing contributors 🌹

Share

Share URL: https://basarat.gitbook.io/typescript/

Author: Basarat
Source Code: https://github.com/basarat/typescript-book/
License: View license

#typescript #opensource

Verdie Murray

1636240140

What Is The Main Difference Of TYPES Vs INTERFACES in TypeScript

TypeScript has two ways of declaring structures of your objects in the form of #types (type aliases) and #interfaces.

In this lesson we will look at the technical differences between these two, when you should use which, along with real world #TypeScript code analysis, and community thoughts

#typescript

Joseph Murray

1624471200

Beginner's Guide to Compilation in Java

Java applications are complied to bytecode then JIT and JVM takes care of code execution. Here you will find some insights about how JIT compiler works.

I am guessing that many of you use Java as your primary language in your day-to-day work. Have you ever thought about why HotSpot is even called HotSpot or what the Tiered Compilation is and how it relates to Java? I will answer these questions and a few others through the course of this article. I will begin this by explaining a few things about compilation itself and the theory behind it.

Turning Source Code to Machine Code

In general, we can differentiate two basic ways of translating human readable code to instructions that can be understood by our computers:

Static (native, AOT) Compilation

After code is written, a compiler will take it and produce a binary executable file. This file will contain set of machine code instructions targeted for particular CPU architecture. Of course the same binary should be able to run on CPUs with similar set of instructions but in more complex cases your binary may fail to run and may require recompiling to meet server requirements. We lose the ability to run on multiple platforms for the benefit of faster execution on a dedicated platform.

Interpretation

Already existing source code will be run and turned into binary code line by line by the interpreter while the exact line is being executed. Thanks to this feature, the application may run on every CPU that has the correct interpreter. On the other hand, it will make the execution slower than in the case of statically compiled languages. We benefit from the ability to run on multiple platforms but lose on execution time.

As you can see both types have their advantages and disadvantages and are dedicated to specific use cases and will probably fail if not used in the correct case. You may ask – if there are only two ways does it mean that Java is an interpreted or a statically compiled language?

#java #jvm #compiler #graalvm #hotspot #compilation #jit compiler #native image #aot #tiered compilation

Lawrence Lesch

1673452161

Compile JSONSchema to TypeScript Type Declarations

json-schema-to-typescript

Compile json schema to typescript typings

Example

Input:

{
  "title": "Example Schema",
  "type": "object",
  "properties": {
    "firstName": {
      "type": "string"
    },
    "lastName": {
      "type": "string"
    },
    "age": {
      "description": "Age in years",
      "type": "integer",
      "minimum": 0
    },
    "hairColor": {
      "enum": ["black", "brown", "blue"],
      "type": "string"
    }
  },
  "additionalProperties": false,
  "required": ["firstName", "lastName"]
}

Output:

export interface ExampleSchema {
  firstName: string;
  lastName: string;
  /**
   * Age in years
   */
  age?: number;
  hairColor?: "black" | "brown" | "blue";
}

Installation

# Using Yarn:
yarn add json-schema-to-typescript

# Or, using NPM:
npm install json-schema-to-typescript --save

Usage

import { compile, compileFromFile } from 'json-schema-to-typescript'

// compile from file
compileFromFile('foo.json')
  .then(ts => fs.writeFileSync('foo.d.ts', ts))

// or, compile a JS object
let mySchema = {
  properties: [...]
}
compile(mySchema, 'MySchema')
  .then(ts => ...)

See server demo and browser demo for full examples.

Options

compileFromFile and compile accept options as their last argument (all keys are optional):

key	type	default	description
additionalProperties	boolean	`true`	Default value for `additionalProperties`, when it is not explicitly set
bannerComment	string	`"/* eslint-disable /\n/\n This file was automatically generated by json-schema-to-typescript.\n* DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,\n* and run json-schema-to-typescript to regenerate this file.\n*/"`	Disclaimer comment prepended to the top of each generated file
cwd	string	`process.cwd()`	Root directory for resolving `$ref`s
declareExternallyReferenced	boolean	`true`	Declare external schemas referenced via `$ref`?
enableConstEnums	boolean	`true`	Prepend enums with `const`?
format	boolean	`true`	Format code? Set this to `false` to improve performance.
ignoreMinAndMaxItems	boolean	`false`	Ignore maxItems and minItems for `array` types, preventing tuples being generated.
maxItems	number	`20`	Maximum number of unioned tuples to emit when representing bounded-size array types, before falling back to emitting unbounded arrays. Increase this to improve precision of emitted types, decrease it to improve performance, or set it to `-1` to ignore `maxItems`.
style	object	`{ bracketSpacing: false, printWidth: 120, semi: true, singleQuote: false, tabWidth: 2, trailingComma: 'none', useTabs: false }`	A Prettier configuration
unknownAny	boolean	`true`	Use `unknown` instead of `any` where possible
unreachableDefinitions	boolean	`false`	Generates code for `$defs` that aren't referenced by the schema.
strictIndexSignatures	boolean	`false`	Append all index signatures with `\| undefined` so that they are strictly typed.
$refOptions	object	`{}`	$RefParser Options, used when resolving `$ref`s

CLI

A CLI utility is provided with this package.

cat foo.json | json2ts > foo.d.ts
# or
json2ts foo.json > foo.d.ts
# or
json2ts foo.json foo.d.ts
# or
json2ts --input foo.json --output foo.d.ts
# or
json2ts -i foo.json -o foo.d.ts
# or (quote globs so that your shell doesn't expand them)
json2ts -i 'schemas/**/*.json'
# or
json2ts -i schemas/ -o types/

You can pass any of the options described above (including style options) as CLI flags. Boolean values can be set to false using the no- prefix.

# generate code for definitions that aren't referenced
json2ts -i foo.json -o foo.d.ts --unreachableDefinitions
# use single quotes and disable trailing semicolons
json2ts -i foo.json -o foo.d.ts --style.singleQuote --no-style.semi

Tests

npm test

Features

title => interface
Primitive types:
- array
- homogeneous array
- boolean
- integer
- number
- null
- object
- string
- homogeneous enum
- heterogeneous enum
Non/extensible interfaces
Custom JSON-schema extensions
Nested properties
Schema definitions
Schema references
Local (filesystem) schema references
External (network) schema references
Add support for running in browser
default interface name
infer unnamed interface name from filename
allOf ("intersection")
anyOf ("union")
oneOf (treated like anyOf)
maxItems (eg)
minItems (eg)
additionalProperties of type
patternProperties (partial support)
extends
required properties on objects (eg)
validateRequired (eg)
literal objects in enum (eg)
referencing schema by id (eg)
custom typescript types via tsType

Custom schema properties:

tsType: Overrides the type that's generated from the schema. Useful for forcing a type to any or when using non-standard JSON schema extensions (eg).
tsEnumNames: Overrides the names used for the elements in an enum. Can also be used to create string enums (eg).

Not expressible in TypeScript:

dependencies (single, multiple)
divisibleBy (eg)
format (eg)
multipleOf (eg)
maximum (eg)
minimum (eg)
maxProperties (eg)
minProperties (eg)
not/disallow
oneOf ("xor", use anyOf instead)
pattern (string, regex)
uniqueItems (eg)

FAQ

JSON-Schema-to-TypeScript is crashing on my giant file. What can I do?

Prettier is known to run slowly on really big files. To skip formatting and improve performance, set the format option to false.

Who uses JSON-Schema-to-TypeScript?

Download Details:

Author: Bcherny
Source Code: https://github.com/bcherny/json-schema-to-typescript

#typescript #json #schema

Arvel Parker

1593156510

Basic Data Types in Python | Python Web Development For Beginners

At the end of 2019, Python is one of the fastest-growing programming languages. More than 10% of developers have opted for Python development.

In the programming world, Data types play an important role. Each Variable is stored in different data types and responsible for various functions. Python had two different objects, and They are mutable and immutable objects.

Table of Contents hide

I Mutable objects

II Immutable objects

III Built-in data types in Python

Mutable objects

The Size and declared value and its sequence of the object can able to be modified called mutable objects.

Mutable Data Types are list, dict, set, byte array

Immutable objects

The Size and declared value and its sequence of the object can able to be modified.

Immutable data types are int, float, complex, String, tuples, bytes, and frozen sets.

id() and type() is used to know the Identity and data type of the object

a**=25+**85j

type**(a)**

output**:<class’complex’>**

b**={1:10,2:“Pinky”****}**

id**(b)**

output**:**238989244168

Built-in data types in Python

a**=str(“Hello python world”)****#str**

b**=int(18)****#int**

c**=float(20482.5)****#float**

d**=complex(5+85j)****#complex**

e**=list((“python”,“fast”,“growing”,“in”,2018))****#list**

f**=tuple((“python”,“easy”,“learning”))****#tuple**

g**=range(10)****#range**

h**=dict(name=“Vidu”,age=36)****#dict**

i**=set((“python”,“fast”,“growing”,“in”,2018))****#set**

j**=frozenset((“python”,“fast”,“growing”,“in”,2018))****#frozenset**

k**=bool(18)****#bool**

l**=bytes(8)****#bytes**

m**=bytearray(8)****#bytearray**

n**=memoryview(bytes(18))****#memoryview**

Numbers (int,Float,Complex)

Numbers are stored in numeric Types. when a number is assigned to a variable, Python creates Number objects.

#signed interger

age**=**18

print**(age)**

Output**:**18

Python supports 3 types of numeric data.

int (signed integers like 20, 2, 225, etc.)

float (float is used to store floating-point numbers like 9.8, 3.1444, 89.52, etc.)

complex (complex numbers like 8.94j, 4.0 + 7.3j, etc.)

A complex number contains an ordered pair, i.e., a + ib where a and b denote the real and imaginary parts respectively).

String

The string can be represented as the sequence of characters in the quotation marks. In python, to define strings we can use single, double, or triple quotes.

# String Handling

‘Hello Python’

#single (') Quoted String

“Hello Python”

# Double (") Quoted String

“”“Hello Python”“”

‘’‘Hello Python’‘’

# triple (‘’') (“”") Quoted String

In python, string handling is a straightforward task, and python provides various built-in functions and operators for representing strings.

The operator “+” is used to concatenate strings and “*” is used to repeat the string.

“Hello”+“python”

output**:****‘Hello python’**

"python "*****2

'Output : Python python ’

#python web development #data types in python #list of all python data types #python data types #python datatypes #python types #python variable type

Compile JSONSchema to TypeScript Type Declarations

json-schema-to-typescript

Example

Installation

Usage

Options

CLI

Tests

Features

Custom schema properties:

Not expressible in TypeScript:

FAQ

JSON-Schema-to-TypeScript is crashing on my giant file. What can I do?

Further Reading

Who uses JSON-Schema-to-TypeScript?

Download Details:

What is GEEK

Buddha Community

The Definitive Guide to TypeScript & Possibly The Best TypeScript Book

Reviews

Get Started

Translations

Other Options

Special Thanks

Share

What Is The Main Difference Of TYPES Vs INTERFACES in TypeScript

Beginner's Guide to Compilation in Java

Java applications are complied to bytecode then JIT and JVM takes care of code execution. Here you will find some insights about how JIT compiler works.

Turning Source Code to Machine Code

Static (native, AOT) Compilation

Interpretation

Compile JSONSchema to TypeScript Type Declarations

json-schema-to-typescript

Example

Installation

Usage

Options

CLI

Tests

Features

Custom schema properties:

Not expressible in TypeScript:

FAQ

JSON-Schema-to-TypeScript is crashing on my giant file. What can I do?

Further Reading

Who uses JSON-Schema-to-TypeScript?

Download Details:

Basic Data Types in Python | Python Web Development For Beginners

Mutable objects

Immutable objects

Built-in data types in Python

Numbers (int,Float,Complex)

String