diff --git a/package.json b/package.json
index 7b22ab7..1493cff 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,6 @@
   "dependencies": {
     "@types/geojson": "7946.0.7",
     "@types/jest": "24.0.11",
-    "@types/json-schema": "7.0.3",
     "@types/node": "11.13.2",
     "@types/shpjs": "3.4.0",
     "geostyler-data": "1.0.0",
diff --git a/src/ShapefileDataParser.spec.ts b/src/ShapefileDataParser.spec.ts
index 52afd95..f73b0ba 100644
--- a/src/ShapefileDataParser.spec.ts
+++ b/src/ShapefileDataParser.spec.ts
@@ -69,24 +69,55 @@ beforeEach(() => {
   parser = new ShapefileDataParser();
 });
 
-it('ShapefileDataParser is defined', () => {
-  expect(ShapefileDataParser).toBeDefined();
-});
+describe('ShapefileDataParser', () => {
+
+  it('…is defined', () => {
+    expect(ShapefileDataParser).toBeDefined();
+  });
 
-describe('ShapefileDataParser implements DataParser', () => {
+  describe('implements DataParser', () => {
+
+    it('…readData is defined', () => {
+      expect(parser.readData).toBeDefined();
+    });
 
-  it('readData is defined', () => {
-    expect(parser.readData).toBeDefined();
   });
 
-});
+  describe('constructor', () => {
 
-describe('readData implementation', () => {
+    it('…creates a GeoJsonDataParser with the passed projections', () => {
+      const parserWithProjection = new ShapefileDataParser('EPSG:3857', 'EPSG:4326');
+      expect(parserWithProjection._geoJsonParser.sourceProjection).toBe('EPSG:3857');
+      expect(parserWithProjection._geoJsonParser.targetProjection).toBe('EPSG:4326');
+    });
 
-  it('can read a Buffer', async () => {
-    const buffer = readFileSync(path.resolve(__dirname, '../data/point.zip'));
-    const data = await parser.readData(buffer);
-    expect(data).toEqual(expectedData);
   });
 
+  describe('readData implementation', () => {
+
+    it('…can read a Buffer', async () => {
+      const buffer = readFileSync(path.resolve(__dirname, '../data/point.zip'));
+      const data = await parser.readData(buffer);
+      expect(data).toEqual(expectedData);
+    });
+
+    it('…rejects the promise if called with invalid (Array)Buffer', (done) => {
+      expect.assertions(1);
+      const buffer = new ArrayBuffer(0);
+      parser.readData(buffer)
+        .catch((e) => {
+          expect(e).toBeDefined();
+        }).finally(done);
+    });
+
+    it('…rejects the promise if called with invalid Argument', (done) => {
+      expect.assertions(1);
+      const buffer = undefined as unknown as ArrayBuffer;
+      parser.readData(buffer)
+        .catch((e) => {
+          expect(e).toBeDefined();
+        }).finally(done);
+    });
+
+  });
 });
diff --git a/src/ShapefileDataParser.ts b/src/ShapefileDataParser.ts
index 2eee50a..46d8e3c 100644
--- a/src/ShapefileDataParser.ts
+++ b/src/ShapefileDataParser.ts
@@ -1,4 +1,5 @@
 import { DataParser, VectorData } from 'geostyler-data';
+import { GeoJSON } from 'geojson';
 import GeoJsonDataParser from 'geostyler-geojson-parser';
 // @ts-ignore // Typing is currently wrong. See PR: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/34623
 import shpjs from 'shpjs';
@@ -15,39 +16,25 @@ export class ShapefileDataParser implements DataParser {
 
   title = 'Shapefile Data Parser';
 
-  sourceProjection: string;
-
-  targetProjection: string;
-
   _geoJsonParser: any;
 
   constructor(sourceProj?: string, targetProj?: string) {
-    this._geoJsonParser = new GeoJsonDataParser();
-    if (sourceProj && targetProj) {
-      this.sourceProjection = sourceProj;
-      this.targetProjection = targetProj;
-    }
+    this._geoJsonParser = new GeoJsonDataParser(sourceProj, targetProj);
   }
 
   /**
    *
    * @param inputData
    */
-  async readData(array: string | Buffer | ArrayBuffer): Promise<VectorData> {
+  readData(array: Buffer | ArrayBuffer): Promise<VectorData> {
     return new Promise<VectorData>((resolve, reject) => {
-      try {
-        shpjs(array)
-          .then((geojson: any) => {
-            if (geojson.type === 'FeatureCollection') {
-              resolve(this._geoJsonParser.readData(geojson));
-            }
-          })
-          .catch((e: any) => {
-            reject(e);
-          });
-      } catch (e) {
-        reject(e);
-      }
+      shpjs(array)
+        .then((geojson: GeoJSON) => {
+            resolve(this._geoJsonParser.readData(geojson));
+        })
+        .catch((e: any) => {
+          reject(e);
+        });
     });
   }