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Merged
raymondfeng merged 2 commits into from
Apr 9, 2020
Merged

feat(core): improve application signal handler registration #5020

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9aec1ac
feat(context): expose debug method to subclasses
raymondfeng Apr 3, 2020
c53833d
feat(core): improve application signal handler registration
raymondfeng Apr 2, 2020
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2 changes: 1 addition & 1 deletion packages/context/package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@
"dependencies": {
"@loopback/metadata": "^2.0.3",
"debug": "^4.1.1",
"@types/debug": "^4.1.5",
"p-event": "^4.1.0",
"tslib": "^1.11.1",
"uuid": "^7.0.3"
Expand All @@ -29,7 +30,6 @@
"@loopback/eslint-config": "^6.0.3",
"@loopback/testlab": "^3.0.0",
"@types/bluebird": "^3.5.30",
"@types/debug": "^4.1.5",
"@types/node": "^10.17.19",
"@types/uuid": "^7.0.2",
"bluebird": "^3.7.2"
Expand Down
64 changes: 62 additions & 2 deletions packages/context/src/__tests__/unit/context.unit.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
// License text available at https://opensource.org/licenses/MIT

import {expect} from '@loopback/testlab';
import {Debugger} from 'debug';
import {format} from 'util';
import {
Binding,
BindingCreationPolicy,
Expand Down Expand Up @@ -44,14 +46,14 @@ describe('Context constructor', () => {
it('generates uuid name if not provided', () => {
const ctx = new Context();
expect(ctx.name).to.match(
/^[0-9A-F]{8}-[0-9A-F]{4}-[1][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i,
/^[0-9A-F]{8}-[0-9A-F]{4}-[4][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i,
);
});

it('adds subclass name as the prefix', () => {
const ctx = new TestContext();
expect(ctx.name).to.match(
/^TestContext-[0-9A-F]{8}-[0-9A-F]{4}-[1][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i,
/^TestContext-[0-9A-F]{8}-[0-9A-F]{4}-[4][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i,
);
});

Expand Down Expand Up @@ -828,6 +830,64 @@ describe('Context', () => {
});
});

describe('debug', () => {
it('allows override of debug from subclasses', () => {
let debugOutput = '';
const myDebug = (formatter: string, ...args: unknown[]) => {
debugOutput = format(formatter, ...args);
};
myDebug.enabled = true;
class MyContext extends Context {
constructor() {
super('my-context');
this._debug = myDebug as Debugger;
}

debug(formatter: string, ...args: unknown[]) {
super.debug(formatter, ...args);
}
}

const myCtx = new MyContext();
myCtx.debug('%s %d', 'number of bindings', 10);
expect(debugOutput).to.eql(`[${myCtx.name}] number of bindings 10`);
});

it('sets up debug for subclasses with the class name', () => {
class MyContext extends Context {
constructor() {
super('my-context');
}

get debugFn() {
return this._debug;
}
}

const myCtx = new MyContext();
expect(myCtx.debugFn.namespace).to.eql('loopback:context:mycontext');
});

it('allows debug namespace for subclasses', () => {
class MyContext extends Context {
constructor() {
super('my-context');
}

getDebugNamespace() {
return 'myapp:my-context';
}

get debugFn() {
return this._debug;
}
}

const myCtx = new MyContext();
expect(myCtx.debugFn.namespace).to.eql('myapp:my-context');
});
});

describe('toJSON() and inspect()', () => {
beforeEach(setupBindings);

Expand Down
72 changes: 53 additions & 19 deletions packages/context/src/context.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,9 @@
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT

import debugFactory from 'debug';
import debugFactory, {Debugger} from 'debug';
import {EventEmitter} from 'events';
import {v1 as uuidv1} from 'uuid';
import {v4 as uuidv4} from 'uuid';
import {Binding, BindingInspectOptions, BindingTag} from './binding';
import {
ConfigurationResolver,
Expand Down Expand Up @@ -40,8 +40,6 @@ import {
ValueOrPromise,
} from './value-promise';

const debug = debugFactory('loopback:context');

/**
* Context provides an implementation of Inversion of Control (IoC) container
*/
Expand Down Expand Up @@ -76,6 +74,21 @@ export class Context extends EventEmitter {
*/
protected configResolver: ConfigurationResolver;

/**
* A debug function which can be overridden by subclasses.
*
* @example
* ```ts
* import debugFactory from 'debug';
* const debug = debugFactory('loopback:context:application');
* export class Application extends Context {
* super('application');
* this._debug = debug;
* }
* ```
*/
protected _debug: Debugger;

/**
* Create a new context.
*
Expand Down Expand Up @@ -113,13 +126,34 @@ export class Context extends EventEmitter {
this.name = name ?? this.generateName();
this.tagIndexer = new ContextTagIndexer(this);
this.subscriptionManager = new ContextSubscriptionManager(this);
this._debug = debugFactory(this.getDebugNamespace());
}

/**
* Get the debug namespace for the context class. Subclasses can override
* this method to supply its own namespace.
*
* @example
* ```ts
* export class Application extends Context {
* super('application');
* }
*
* protected getDebugNamespace() {
* return 'loopback:context:application';
* }
* ```
*/
protected getDebugNamespace() {
if (this.constructor === Context) return 'loopback:context';
const name = this.constructor.name.toLowerCase();
return `loopback:context:${name}`;
}

private generateName() {
const id = uuidv1();
let prefix = `${this.constructor.name}-`;
if (prefix === 'Context-') prefix = '';
return `${prefix}${id}`;
const id = uuidv4();
if (this.constructor === Context) return id;
return `${this.constructor.name}-${id}`;
}

/**
Expand All @@ -135,14 +169,14 @@ export class Context extends EventEmitter {
* as the prefix
* @param args - Arguments for the debug
*/
private _debug(...args: unknown[]) {
protected debug(...args: unknown[]) {
/* istanbul ignore if */
if (!debug.enabled) return;
if (!this._debug.enabled) return;
const formatter = args.shift();
if (typeof formatter === 'string') {
debug(`[%s] ${formatter}`, this.name, ...args);
this._debug(`[%s] ${formatter}`, this.name, ...args);
} else {
debug('[%s] ', this.name, formatter, ...args);
this._debug('[%s] ', this.name, formatter, ...args);
}
}

Expand Down Expand Up @@ -184,7 +218,7 @@ export class Context extends EventEmitter {
*/
add(binding: Binding<unknown>): this {
const key = binding.key;
this._debug('[%s] Adding binding: %s', key);
this.debug('[%s] Adding binding: %s', key);
let existingBinding: Binding | undefined;
const keyExists = this.registry.has(key);
if (keyExists) {
Expand Down Expand Up @@ -261,14 +295,14 @@ export class Context extends EventEmitter {
},
);
if (configResolver) {
debug(
this.debug(
'Custom ConfigurationResolver is loaded from %s.',
ContextBindings.CONFIGURATION_RESOLVER.toString(),
);
this.configResolver = configResolver;
} else {
// Fallback to DefaultConfigurationResolver
debug('DefaultConfigurationResolver is used.');
this.debug('DefaultConfigurationResolver is used.');
this.configResolver = new DefaultConfigurationResolver(this);
}
}
Expand Down Expand Up @@ -340,7 +374,7 @@ export class Context extends EventEmitter {
* @returns true if the binding key is found and removed from this context
*/
unbind(key: BindingAddress): boolean {
this._debug('Unbind %s', key);
this.debug('Unbind %s', key);
key = BindingKey.validate(key);
const binding = this.registry.get(key);
// If not found, return `false`
Expand Down Expand Up @@ -378,7 +412,7 @@ export class Context extends EventEmitter {
* which is created per request.
*/
close() {
this._debug('Closing context...');
this.debug('Closing context...');
this.subscriptionManager.close();
this.tagIndexer.close();
}
Expand Down Expand Up @@ -577,7 +611,7 @@ export class Context extends EventEmitter {
keyWithPath: BindingAddress<ValueType>,
optionsOrSession?: ResolutionOptionsOrSession,
): Promise<ValueType | undefined> {
this._debug('Resolving binding: %s', keyWithPath);
this.debug('Resolving binding: %s', keyWithPath);
return this.getValueOrPromise<ValueType | undefined>(
keyWithPath,
optionsOrSession,
Expand Down Expand Up @@ -645,7 +679,7 @@ export class Context extends EventEmitter {
keyWithPath: BindingAddress<ValueType>,
optionsOrSession?: ResolutionOptionsOrSession,
): ValueType | undefined {
this._debug('Resolving binding synchronously: %s', keyWithPath);
this.debug('Resolving binding synchronously: %s', keyWithPath);

const valueOrPromise = this.getValueOrPromise<ValueType>(
keyWithPath,
Expand Down
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