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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
const Cm = Components.manager;
export var MockRegistrar = Object.freeze({
_registeredComponents: new Map(),
_originalCIDs: new Map(),
get registrar() {
return Cm.QueryInterface(Ci.nsIComponentRegistrar);
},
/**
* Register a mock to override target interfaces.
* The target interface may be accessed through _genuine property of the mock.
* If you register multiple mocks to the same contract ID, you have to call
* unregister in reverse order. Otherwise the previous factory will not be
* restored.
*
* @param contractID The contract ID of the interface which is overridden by
the mock.
* e.g. "@mozilla.org/file/directory_service;1"
* @param mock An object which implements interfaces for the contract ID.
* @param args An array which is passed in the constructor of mock.
*
* @return The CID of the mock.
*/
register(contractID, mock, args) {
let originalCID;
let originalFactory;
try {
originalCID = this._originalCIDs.get(contractID);
if (!originalCID) {
originalCID = this.registrar.contractIDToCID(contractID);
this._originalCIDs.set(contractID, originalCID);
}
originalFactory = Cm.getClassObject(originalCID, Ci.nsIFactory);
} catch (e) {
// There's no original factory. Ignore and just register the new
// one.
}
let cid = Services.uuid.generateUUID();
let factory = {
createInstance(iid) {
let wrappedMock;
if (mock.prototype && mock.prototype.constructor) {
wrappedMock = Object.create(mock.prototype);
mock.apply(wrappedMock, args);
} else if (typeof mock == "function") {
wrappedMock = mock();
} else {
wrappedMock = mock;
}
if (originalFactory) {
try {
let genuine = originalFactory.createInstance(iid);
wrappedMock._genuine = genuine;
} catch (ex) {
console.error(
"MockRegistrar: Creating original instance failed",
ex
);
}
}
return wrappedMock.QueryInterface(iid);
},
QueryInterface: ChromeUtils.generateQI(["nsIFactory"]),
};
this.registrar.registerFactory(
cid,
"A Mock for " + contractID,
contractID,
factory
);
this._registeredComponents.set(cid, {
contractID,
factory,
originalCID,
});
return cid;
},
/**
* Unregister the mock.
*
* @param cid The CID of the mock.
*/
unregister(cid) {
let component = this._registeredComponents.get(cid);
if (!component) {
return;
}
this.registrar.unregisterFactory(cid, component.factory);
if (component.originalCID) {
// Passing `null` for the factory re-maps the contract ID to the
// entry for its original CID.
this.registrar.registerFactory(
component.originalCID,
"",
component.contractID,
null
);
}
this._registeredComponents.delete(cid);
},
/**
* Unregister all registered mocks.
*/
unregisterAll() {
for (let cid of this._registeredComponents.keys()) {
this.unregister(cid);
}
},
});