Add Test for DPT12.

tests/DPT012.test.ts

@@ -9,5 +9,42 @@ import { compareBuffers } from "./util"
 describe("Test DPT012", (): void => {
 
   let dpt = new DPT12();
+  it("Decode buffer acceptable", async function () {
+    let value = 0x24101011
+    let buffer = Buffer.from([0x24, 0x10, 0x10, 0x11])
+    const decoded = dpt.decoder(buffer)
+    expect(decoded).is.equal(value);
+  });
 
+  it("Decode empty buffer", async function () {
+    let bufferEmpty = Buffer.from([])
+    var testFunction = function () {
+      const value = dpt.decoder(bufferEmpty)
+    }
+    expect(testFunction).to.throw(BufferLengthError);
+  });
+
+  it("Decode oversized buffer", async function () {
+    let bufferBiggerSize = Buffer.from([0x20, 0x15, 0, 0, 0])
+
+    var testFunction = function () {
+      const value = dpt.decoder(bufferBiggerSize)
+    }
+    expect(testFunction).to.throw(BufferLengthError);
+  });
+
+  /* Encoder tests */
+  it("encode valid", async function () {
+    let value = 0x15f040cc
+    let buffer = Buffer.from([0x15, 0xf0, 0x40, 0xcc])
+
+    expect(compareBuffers(dpt.encoder(value), buffer)).is.true;
+  });
+
+  it("encode undefined", async function () {
+    var testFunction = function () {
+      const value = dpt.encoder(undefined)
+    }
+    expect(testFunction).to.throw(InvalidValueError);
+  });
 });