typescript core decorators

typescript wrappers decorators and services

Motivation: decorators is cool :heart: :fire:

table of decorators:

decorator	arguments	description	target	service
log	toConosle - default is false	logging all method calls and set to logService	class	logService
timerify	-	record function time execution. Also have statistic as total time and long execing function	method	performanceService
select	map - Map<K,V> ot WeakMap key - K	Select value by key from map like collection	property	-
pure	-	checking function or argument for not undefined and throw error if is not pure	method, argument	-
autowired	args: any[]	creating new instance of type annotation	property	-
save	handler: () => never	make function save - if handler is not set - don't stop executing program	method	-
trigger	ProxyObject	make class as Proxy. Make intercept functions, contructor calling and may redirect to new target	class	-

want get more usage? see examples below

usage: @autowired() decorator:

1import { autowired } from '../src/decorators/common';
2
3class Autowired {
4    public readonly someReadOnlyProp = 4;
5}
6
7class Autowired2 {
8    constructor(private prop: string) {
9    }
10}
11
12class Temp {
13
14    @autowired('123')
15    public autoWired2!: Autowired2; // create Autowired2 instance
16
17    @autowired()
18    public autoWired!: Autowired; // note: ! symbol for strict mode
19}
20
21const temp = new Temp();
22console.dir(temp.autoWired); // Autowired {someReadOnlyProp: 4}
23console.dir(temp.autoWired2); // Autowired2 {prop: "123"}

usage: @log() decorator

1import { log } from 'ts-core-decorators/core/decorators/common';
2import { logService } from 'ts-core-decorators/core/services/log';
3
4@log({ toConsole: true })
5class Temp {
6  constructor() {}
7
8  someFn(test: number) {
9    return test;
10  }
11}
12
13const a = new Temp();
14a.someFn(21);
15
16logService.writeToFile('./logger.json'); // writing result to file

another example:

1import { Log } from 'ts-core-decorators/core/decorators/common';
2import { logService } from 'ts-core-decorators/core/services/log';
3
4@Log()
5class Temp {
6  constructor() {}
7
8  someFn(test: number) {
9    return test;
10  }
11}
12
13const a = new Temp();
14a.someFn(21);
15
16logService.writeToFile('./logger.json'); // writing result to file

usage: @timerify() decorator

1import { timerify } from 'ts-core-decorators/core/decorators/performance';
2
3import { PerformanceService } from 'ts-core-decorators/core/services/performance';
4
5const performance = PerformanceService.connect(); // one time only. for example on prepare hook
6
7class Temp {
8  constructor() {}
9
10  @timerify()
11  public longTask() {
12    return 500;
13  }
14}
15
16new Temp().lognTask(); // usage
17
18performance.profiler.writeToFile('./profiler.json'); // write performance information to file
19performance.disconect(); // clear GC from performance information. for example on destroy

usage: @select() decorator

1import { select } from 'ts-core-decorators/core/decorators/collections';
2
3const map: Map<string, number> = new Map();
4
5map.set('test', 123);
6map.set('test2', 4564);
7
8class Temp {
9  @select(map, 'test')
10  public test?: number; // 123
11
12  constructor() {
13    console.log(this.test);
14  }
15}

usage: @pure() decorator

1import { pure } from 'ts-core-decorators/core/decorators/common';
2
3class Temp {
4  constructor() {}
5
6  @pure<number>()
7  public someFn(@pure<number>() someArg?: number, anotherNumber?: number): number {
8    return someArg || 1;
9  }
10
11  @pure<number>()
12  public anotherFn(@pure<number>() someArg?: number, @pure<number>() anotherNumber?: number): number {
13    return someArg || 1;
14  }
15}
16const temp = new Temp();
17
18temp.someFn(2, 3);
19temp.anotherFn(1); // runtime error here. someArg is defined, but anotherNumber is not

1import { save } from 'ts-core-decorators/core/decorators/common';
2class SaveDecoratorExample {
3    @save()
4    public unsaveFunction(arg: any) {
5        return arg.length > 0;
6    }
7}
8const saveDecoratorExample = new SaveDecoratorExample();
9
10console.log('start executing');
11saveDecoratorExample.unsaveFunction(null);
12console.log('continue executing');
13// start executing
14// cannot read property 'length' of null
15// continue executing
16

1import { trigger } from 'ts-core-decorators/core/decorators/common';
2
3@trigger({
4    construct: function (target: any, arrayList: any) {
5        const instance = new target(...arrayList) as Temp;
6        // can use Temp methods here
7        console.dir(instance);
8        return instance;
9    },
10})
11class Temp {
12    constructor() { }
13
14    public longTask() {
15        console.log('long task executed');
16        return 500;
17    }
18}
19
20const temp = new Temp();
21temp.longTask();
22

More examples? Visit examples folder for more.

Still question or problem? Write issue. Let's create more useful decorators together!