feat(Bus): Add Bus factory

package.json

@@ -42,7 +42,11 @@
     }
   },
   "dependencies": {
+    "@types/bluebird": "^3.5.24",
+    "@types/i2c-bus": "^1.0.19",
     "@types/node": "^10.12.12",
+    "bluebird": "^3.5.3",
+    "i2c-bus": "^4.0.6",
     "typescript": "^3.2.2"
   }
 }

src/Bus/Bus.ts

@@ -0,0 +1,164 @@
+import { promisifyAll } from 'bluebird';
+import { I2cBusFuncs, open as openI2cBusFn } from 'i2c-bus';
+
+import { I2cBusPromised } from '../types';
+
+import BusError from './BusError';
+
+export interface BusInterface {
+  readonly busNumber: number;
+  readonly i2cBus: I2cBusPromised | null;
+  readonly isOpen: boolean;
+
+  open: () => Promise<BusInterface>;
+  close: () => Promise<BusInterface>;
+
+  i2cFuncs: () => Promise<I2cBusFuncs>;
+  scan: () => Promise<number[]>;
+
+  i2cRead: (address: number, length: number, buffer: Buffer) => Promise<number>;
+  i2cWrite: (address: number, length: number, buffer: Buffer) => Promise<number>;
+
+  receiveByte: (address: number) => Promise<number>;
+  sendByte: (address: number, byte: number) => Promise<void>;
+
+  readByte: (address: number, command: number) => Promise<number>;
+  readI2cBlock: (address: number, command: number, length: number, buffer: Buffer) => Promise<number>;
+  readWord: (address: number, command: number) => Promise<number>;
+
+  writeByte: (address: number, command: number, byte: number) => Promise<void>;
+  writeWord: (address: number, command: number, word: number) => Promise<void>;
+  writeI2cBlock: (address: number, command: number, length: number, buffer: Buffer) => Promise<number>;
+}
+
+export default ({ busNumber = 1, openI2cBus = openI2cBusFn } = {}): BusInterface => {
+  let i2cBus: I2cBusPromised | null = null;
+  let isOpen: boolean = false;
+
+  return {
+    get busNumber() {
+      return busNumber;
+    },
+    get i2cBus() {
+      return i2cBus;
+    },
+    get isOpen() {
+      return isOpen;
+    },
+
+    open() {
+      return new Promise((resolve, reject) => {
+        i2cBus = promisifyAll<I2cBusPromised>(openI2cBus(this.busNumber, (error: Error) => {
+          if (error) {
+            reject(`Error opening i2c bus: ${error.message}`);
+          }
+
+          isOpen = true;
+
+          resolve(this);
+        }) as I2cBusPromised);
+      });
+    },
+    async close() {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      await i2cBus.closeAsync();
+
+      isOpen = false;
+      i2cBus = null;
+
+      return this;
+    },
+
+    async i2cFuncs() {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.i2cFuncsAsync();
+    },
+    async scan() {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.scanAsync();
+    },
+
+    async i2cRead(address: number, length: number, buffer: Buffer) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.i2cReadAsync(address, length, buffer);
+    },
+    async i2cWrite(address: number, length: number, buffer: Buffer) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.i2cWriteAsync(address, length, buffer);
+    },
+
+    async receiveByte(address: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.receiveByteAsync(address);
+    },
+    async sendByte(address: number, byte: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.sendByteAsync(address, byte);
+    },
+
+    async readByte(address: number, command: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.readByteAsync(address, command);
+    },
+    async readWord(address: number, command: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.readWordAsync(address, command);
+    },
+    async readI2cBlock(address: number, command: number, length: number, buffer: Buffer) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.readI2cBlockAsync(address, command, length, buffer);
+    },
+
+    async writeByte(address: number, command: number, byte: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.writeByteAsync(address, command, byte);
+    },
+    async writeWord(address: number, command: number, word: number) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.writeWordAsync(address, command, word);
+    },
+    async writeI2cBlock(address: number, command: number, length: number, buffer: Buffer) {
+      if (!i2cBus || !isOpen) {
+        throw new BusError('BusInterface is not open', busNumber);
+      }
+
+      return i2cBus.writeI2cBlockAsync(address, command, length, buffer);
+    },
+  };
+};

src/Bus/BusError.ts

@@ -0,0 +1,13 @@
+export default class BusError extends Error {
+  public busNumber: number;
+
+  constructor(msg: string, busNumber: number) {
+    super(msg);
+
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, BusError);
+    }
+
+    this.busNumber = busNumber;
+  }
+}

src/Bus/index.ts

@@ -0,0 +1,4 @@
+import Bus, { BusInterface } from './Bus';
+import BusError from './BusError';
+
+export { Bus, BusError, BusInterface };

src/index.ts

@@ -0,0 +1,3 @@
+import { Bus, BusError, BusInterface } from './Bus';
+
+export { Bus, BusError, BusInterface };

yarn.lock

@@ -139,12 +139,24 @@
     into-stream "^4.0.0"
     lodash "^4.17.4"
 
+"@types/bluebird@^3.5.24":
+  version "3.5.24"
+  resolved "https://registry.yarnpkg.com/@types/bluebird/-/bluebird-3.5.24.tgz#11f76812531c14f793b8ecbf1de96f672905de8a"
+  integrity sha512-YeQoDpq4Lm8ppSBqAnAeF/xy1cYp/dMTif2JFcvmAbETMRlvKHT2iLcWu+WyYiJO3b3Ivokwo7EQca/xfLVJmg==
+
+"@types/i2c-bus@^1.0.19":
+  version "1.0.19"
+  resolved "https://registry.yarnpkg.com/@types/i2c-bus/-/i2c-bus-1.0.19.tgz#58a9208370abf4d8e910ae37b4aa4cfbaecbc7d4"
+  integrity sha512-kdzu2dQz6rEdPVNzyHFxtmr78p1+X2RG4JZo7OTTdb9i122CGhSf8oNoR+aMcKW+0UhTOnCaNRbBWFh6h1aEag==
+  dependencies:
+    "@types/node" "*"
+
 "@types/jest@^23.3.10":
   version "23.3.10"
   resolved "https://registry.yarnpkg.com/@types/jest/-/jest-23.3.10.tgz#4897974cc317bf99d4fe6af1efa15957fa9c94de"
   integrity sha512-DC8xTuW/6TYgvEg3HEXS7cu9OijFqprVDXXiOcdOKZCU/5PJNLZU37VVvmZHdtMiGOa8wAA/We+JzbdxFzQTRQ==
 
-"@types/node@^10.12.12":
+"@types/node@*", "@types/node@^10.12.12":
   version "10.12.12"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-10.12.12.tgz#e15a9d034d9210f00320ef718a50c4a799417c47"
   integrity sha512-Pr+6JRiKkfsFvmU/LK68oBRCQeEg36TyAbPhc2xpez24OOZZCuoIhWGTd39VZy6nGafSbxzGouFPTFD/rR1A0A==
@@ -661,14 +673,19 @@ bin-links@^1.1.2:
     graceful-fs "^4.1.11"
     write-file-atomic "^2.3.0"
 
+bindings@^1.3.0:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/bindings/-/bindings-1.3.1.tgz#21fc7c6d67c18516ec5aaa2815b145ff77b26ea5"
+  integrity sha512-i47mqjF9UbjxJhxGf+pZ6kSxrnI3wBLlnGI2ArWJ4r0VrvDS7ZYXkprq/pLaBWYq4GM0r4zdHY+NNRqEMU7uew==
+
 block-stream@*:
   version "0.0.9"
   resolved "https://registry.yarnpkg.com/block-stream/-/block-stream-0.0.9.tgz#13ebfe778a03205cfe03751481ebb4b3300c126a"
   integrity sha1-E+v+d4oDIFz+A3UUgeu0szAMEmo=
   dependencies:
     inherits "~2.0.0"
 
-bluebird@^3.5.0, bluebird@^3.5.1, bluebird@~3.5.1:
+bluebird@^3.5.0, bluebird@^3.5.1, bluebird@^3.5.3, bluebird@~3.5.1:
   version "3.5.3"
   resolved "https://registry.yarnpkg.com/bluebird/-/bluebird-3.5.3.tgz#7d01c6f9616c9a51ab0f8c549a79dfe6ec33efa7"
   integrity sha512-/qKPUQlaW1OyR51WeCPBvRnAlnZFUJkCSG5HzGnuIqhgyJtF+T94lFnn33eiazjRm2LAHVy2guNnaq48X9SJuw==
@@ -2342,6 +2359,14 @@ humanize-ms@^1.2.1:
   dependencies:
     ms "^2.0.0"
 
+i2c-bus@^4.0.6:
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/i2c-bus/-/i2c-bus-4.0.6.tgz#5a3114a06c66fc1c91afb93a972df6c4815e5311"
+  integrity sha512-9I/JxojEPnFvEdw3whDQlgQ35NHOGCt0mADfImQVhDz5elhMQm26qhR+XnWVHtt3zIf9B9Wun4x8pMaeuGxlKQ==
+  dependencies:
+    bindings "^1.3.0"
+    nan "^2.11.1"
+
 [email protected], iconv-lite@^0.4.4, iconv-lite@~0.4.13:
   version "0.4.24"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.24.tgz#2022b4b25fbddc21d2f524974a474aafe733908b"
@@ -3976,7 +4001,7 @@ mute-stream@~0.0.4:
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
   integrity sha1-MHXOk7whuPq0PhvE2n6BFe0ee6s=
 
-nan@^2.9.2:
+nan@^2.11.1, nan@^2.9.2:
   version "2.11.1"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.11.1.tgz#90e22bccb8ca57ea4cd37cc83d3819b52eea6766"
   integrity sha512-iji6k87OSXa0CcrLl9z+ZiYSuR2o+c0bGuNmXdrhTQTakxytAFsC56SArGYoiHlJlFoHSnvmhpceZJaXkVuOtA==