From f2d396168614492c19228cb75e05aedcdc98e853 Mon Sep 17 00:00:00 2001
From: Frieder Schlesier <frieder@fschl.de>
Date: Wed, 9 Nov 2022 20:28:42 +0100
Subject: [PATCH] initial commit

---
 .gitignore        |  1 +
 README.md         | 30 +++++++++++++++++++++++++++
 app.js            | 17 ++++++++++++++++
 gpio.js           | 27 ++++++++++++++++++++++++
 package.json      | 22 ++++++++++++++++++++
 test/gpio.test.js | 52 +++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 149 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 README.md
 create mode 100644 app.js
 create mode 100644 gpio.js
 create mode 100644 package.json
 create mode 100644 test/gpio.test.js

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..843f7a9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..802d397
--- /dev/null
+++ b/README.md
@@ -0,0 +1,30 @@
+# GPIO-mock test nodejs
+
+test gpio in a container (without them being physically available)
+
+idea/initial mock forked from: https://github.com/sitepoint-editors/TddWithGpio
+
+Article: https://www.sitepoint.com/getting-started-with-the-raspberry-pi-gpio-pins-in-node-js/
+
+## run dev
+
+~~~shell
+docker run -it --rm -v $(pwd):/app -w /app node:lts bash
+~~~
+
+followed by 
+
+~~~shell
+npm install
+npm run test
+~~~
+
+## Jest
+
+https://jestjs.io/docs/using-matchers
+
+## TODO
+
+check this out: https://stackoverflow.com/questions/50066138/mock-fs-function-with-jest
+
+is this going to be a problem? https://stackoverflow.com/questions/62568294/nodejs-fs-watch-inside-docker-container-detects-changes-twice
diff --git a/app.js b/app.js
new file mode 100644
index 0000000..19a13c8
--- /dev/null
+++ b/app.js
@@ -0,0 +1,17 @@
+var gpio = require('./gpio');
+
+gpio.open(16, 'out', function () {
+  var on = 0;
+
+  var blinker = setInterval(function () {
+    gpio.write(16, on, function () {
+      on = (on + 1) % 2;
+
+      console.log('ON = ' + on);
+    });
+  }, 1000);
+
+  setTimeout(function () {
+    clearInterval(blinker);
+  }, 12000);
+});
diff --git a/gpio.js b/gpio.js
new file mode 100644
index 0000000..a5ffbc7
--- /dev/null
+++ b/gpio.js
@@ -0,0 +1,27 @@
+var fs = require('fs');
+
+// Post 3.18.x kernel
+var sysFsPath = '/sys/class/gpio/gpio';
+var pinMapping = {
+  '16': 23
+};
+
+function open(pinNumber, direction, callback) {
+  const path = sysFsPath + pinMapping[pinNumber] + '/direction';
+
+  fs.writeFile(path, direction, (callback || noOp));
+}
+
+function write(pinNumber, value, callback) {
+  const path = sysFsPath + pinMapping[pinNumber] + '/value';
+  value = !!value ? '1' : '0';
+
+  fs.writeFile(path, value, 'utf8', callback);
+}
+
+function noOp() {}
+
+module.exports = {
+  open: open,
+  write: write
+};
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..6b536b7
--- /dev/null
+++ b/package.json
@@ -0,0 +1,22 @@
+{
+    "name": "tdd-with-gpio",
+    "version": "0.0.1",
+    "main": "app.js",
+    "scripts": {
+        "start": "node app.js",
+        "test": "jest"
+
+    },
+    "author": {
+        "name": "CR",
+        "email": "reyesc@gmail.com"
+    },
+    "devDependencies": {
+        "jest": "^29.3.1",
+        "mock-fs": "^5.2.0"
+    },
+    "dependencies": {
+        "fix": "^0.0.6",
+        "mqtt": "^4.3.7"
+    }
+}
diff --git a/test/gpio.test.js b/test/gpio.test.js
new file mode 100644
index 0000000..d226c0e
--- /dev/null
+++ b/test/gpio.test.js
@@ -0,0 +1,52 @@
+var mock = require('mock-fs');
+var fs = require('fs');
+
+var gpio = require('../gpio');
+
+describe('GPIO API', function () {
+    it('opens a pin with out', function (done) {
+        mock({
+            '/sys/class/gpio/gpio23/direction': ''
+        });
+
+        gpio.open(16, 'out', function () {
+            const direction = fs.readFileSync('/sys/class/gpio/gpio23/direction').toString();
+
+            expect(direction).toEqual('out');
+
+            done();
+        });
+    });
+
+    it('writes to a pin with a high value', function (done) {
+        mock({
+            '/sys/class/gpio/gpio23/value': '0'
+        });
+
+        gpio.write(16, 5, function () {
+            const value = fs.readFileSync('/sys/class/gpio/gpio23/value').toString();
+
+            expect(value).toEqual('1');
+
+            done();
+        });
+    });
+
+    it('writes to a pin with a low value', function (done) {
+        mock({
+            '/sys/class/gpio/gpio23/value': '1'
+        });
+
+        gpio.write(16, 0, function () {
+            const value = fs.readFileSync('/sys/class/gpio/gpio23/value').toString();
+
+            expect(value).toEqual('0');
+
+            done();
+        });
+    });
+
+    afterEach(function () {
+        mock.restore();
+    });
+});