put file paths into constants

__tests__/fileHash.test.ts

 import assert from 'assert';
 import {hashFile, isHashValid} from '../src/utils/fileHasher';
+
+const PATH_TO_TEST_CONTRACT_0 = '__tests__/test data/test-arbeidskontrakt-00.pdf';
+const PATH_TO_TEST_CONTRACT_1 = '__tests__/test data/test-arbeidskontrakt-01.pdf';
+const TEST_CONTRACT_0_HASH = 'a21888557401c7e6e8fc12123e48fe11597084b67a7127dd7844a32006210d9d';
+
 describe('the file hash script', function (){
 	describe('the hash file function', function() {
 		it('should create a hash of a file', function () {
-			const fileHash = hashFile('test/test data/test-arbeidskontrakt-00.pdf');
-			const expectedHash = 'a21888557401c7e6e8fc12123e48fe11597084b67a7127dd7844a32006210d9d';
+			const fileHash = hashFile(PATH_TO_TEST_CONTRACT_0);
+			const expectedHash = TEST_CONTRACT_0_HASH;
 			assert.equal(fileHash, expectedHash);
 
 		});
@@ -16,13 +21,13 @@ describe('the file hash script', function (){
 	});
 	describe('the isHashValid function', function (){
 		it('should return true if the same file is hashed twice', function () {
-			const fileHash1 = hashFile('test/test data/test-arbeidskontrakt-00.pdf');
-			const isEqual = isHashValid(fileHash1, 'test/test data/test-arbeidskontrakt-00.pdf');
+			const fileHash1 = hashFile(PATH_TO_TEST_CONTRACT_0);
+			const isEqual = isHashValid(fileHash1, PATH_TO_TEST_CONTRACT_0);
 			assert.equal(isEqual, true);
 		});
 		it('should return false if two different files are hashed', function () {
-			const fileHash1 = hashFile('test/test data/test-arbeidskontrakt-00.pdf');
-			const isEqual = isHashValid(fileHash1, 'test/test data/test-arbeidskontrakt-01.pdf');
+			const fileHash1 = hashFile(PATH_TO_TEST_CONTRACT_0);
+			const isEqual = isHashValid(fileHash1, PATH_TO_TEST_CONTRACT_1);
 			assert.equal(isEqual, false);
 		});
 	});