Introduce api._getEffectiveAuth and use it on listDevices({})

Author: Joe Goggins

src/Particle.js

@@ -407,6 +407,7 @@ class Particle {
 			uri = '/v1/devices';
 		}
 
+		auth = this._getEffectiveAuth(auth);
 		return this.get({ uri, auth, headers, query, context });
 	}
 
@@ -2107,7 +2108,21 @@ class Particle {
 	setDefaultAuth(auth){
 		this._defaultAuth = auth;
 	}
-
+	/**
+	 * Return provided token if truthy else use default auth if truthy else undefined
+	 * @param {*} auth Optional auth token or undefined
+	 * @private
+	 * @returns {String|undefined} a Particle auth token or undefined
+	 */
+	_getEffectiveAuth(auth) {
+		if (auth) {
+			return auth;
+		} else if (this._defaultAuth) {
+			return this._defaultAuth;
+		} else {
+			return undefined;
+		}
+	}
 	/**
 	 * API URI to access a device
 	 * @param  {Object} options Options for this API call

test/Particle.spec.js

@@ -370,6 +370,18 @@ describe('ParticleAPI', () => {
 		});
 
 		describe('.listDevices', () => {
+			describe('uses effective auth', () => {
+				afterEach(() => {
+					sinon.restore();
+				});
+				it('calls this._getEffectiveAuth', async () => {
+					sinon.stub(api, '_getEffectiveAuth');
+					sinon.stub(api, 'get'); // don't actually call the real method
+					await api.listDevices(props);
+					expect(api._getEffectiveAuth).to.have.property('callCount', 1);
+				});
+			});
+
 			describe('user scope', () => {
 				it('generates request', () => {
 					return api.listDevices(props).then((results) => {
@@ -2728,4 +2740,29 @@ describe('ParticleAPI', () => {
 			expect(api._defaultAuth).to.eql(auth);
 		});
 	});
+
+	describe('_getEffectiveAuth(auth)', () => {
+		afterEach(() => {
+			sinon.restore();
+		});
+
+		it('returns provided value when provided value is truthy', () => {
+			const expectedReturnValue = 'pass through';
+			expect(api._getEffectiveAuth(expectedReturnValue)).to.eql(expectedReturnValue);
+		});
+
+		it('returns value of _defaultAuth when provided value is NOT truthy', () => {
+			const providedValue = undefined;
+			const expectedReturnValue = 'default auth value';
+			api.setDefaultAuth(expectedReturnValue);
+			expect(api._getEffectiveAuth(providedValue)).to.eql(expectedReturnValue);
+		});
+
+		it('returns undefined when both provided value and _defaultAuth are NOT truthy', () => {
+			const providedValue = undefined;
+			const expectedReturnValue = undefined;
+			api.setDefaultAuth(undefined);
+			expect(api._getEffectiveAuth(providedValue)).to.eql(expectedReturnValue);
+		});
+	});
 });