diff --git a/dub.json b/dub.json
index 63601d1..fcd5a94 100644
--- a/dub.json
+++ b/dub.json
@@ -10,5 +10,19 @@
 	},
 	"description": "A minimal D application.",
 	"copyright": "Copyright © 2017, Johannes Loher",
-	"license": "MIT"
+	"license": "MIT",
+	"targetType": "executable",
+	"configurations": [
+        { "name": "executable" },
+        {
+            "name": "unittest",
+            "targetType": "executable",
+            "preBuildCommands": ["dub run unit-threaded -c gen_ut_main -- -f gen/ut.d"],
+            "mainSourceFile": "gen/ut.d",
+            "excludedSourceFiles": ["source/app.d"],
+            "dependencies": {
+                "unit-threaded": "~>0.7.28"
+            }
+        }
+    ]
 }
diff --git a/source/fahrplanparser.d b/source/fahrplanparser.d
index 952c487..64ca475 100644
--- a/source/fahrplanparser.d
+++ b/source/fahrplanparser.d
@@ -1,12 +1,17 @@
 module fahrplanparser;
 
+import kxml.xml : readDocument, XmlNode;
+
 import std.algorithm : map;
 import std.array : empty, front;
 import std.conv : to;
 import std.datetime : dur, TimeOfDay, DateTimeException;
 import std.string : format;
 
-import kxml.xml : readDocument, XmlNode;
+version (unittest)
+{
+    import unit_threaded;
+}
 
 import substitution;
 
@@ -50,22 +55,74 @@ auto parsedFahrplan(in string data)
 {
     import std.array : array;
 
-    auto xml = "";
-    assert(xml.parsedFahrplan.array == []);
+    "".parsedFahrplan.array.shouldEqual([]);
 
-    xml = "<efa><dps></dps></efa>";
-    assert(xml.parsedFahrplan.array == []);
+    "<efa><dps></dps></efa>".parsedFahrplan.array.shouldEqual([]);
 
-    xml = "<efa><dps><dp><realtime>1</realtime><st><t>1224</t><rt>1242</rt></st><m><nu>6</nu><des>Wernerwerkstraße</des></m></dp></dps></efa>";
-    assert(xml.parsedFahrplan.array == [["direction" : "Wernerwerkstraße",
+    q"[
+        <efa>
+            <dps>
+                <dp>
+                    <realtime>1</realtime>
+                    <st>
+                        <t>1224</t>
+                        <rt>1242</rt>
+                    </st>
+                    <m>
+                        <nu>6</nu>
+                        <des>Wernerwerkstraße</des>
+                    </m>
+                </dp>
+            </dps>
+        </efa>
+    ]".parsedFahrplan.array.shouldEqual([["direction" : "Wernerwerkstraße",
             "line" : "6", "departure" : "12:24", "delay" : "18"]]);
 
-    xml = "<efa><dps><dp><realtime>0</realtime><st><t>1224</t></st><m><nu>6</nu><des>Wernerwerkstraße</des></m></dp></dps></efa>";
-    assert(xml.parsedFahrplan.array == [["direction" : "Wernerwerkstraße",
+    q"[
+        <efa>
+            <dps>
+                <dp>
+                    <realtime>0</realtime>
+                    <st>
+                        <t>1224</t>
+                    </st>
+                    <m>
+                        <nu>6</nu>
+                        <des>Wernerwerkstraße</des>
+                    </m>
+                </dp>
+            </dps>
+        </efa>
+    ]".parsedFahrplan.array.shouldEqual([["direction" : "Wernerwerkstraße",
             "line" : "6", "departure" : "12:24", "delay" : "0"]]);
 
-    xml = "<efa><dps><dp><realtime>0</realtime><st><t>1224</t></st><m><nu>6</nu><des>Wernerwerkstraße</des></m></dp><dp><realtime>1</realtime><st><t>1353</t><rt>1356</rt></st><m><nu>11</nu><des>Burgweinting</des></m></dp></dps></efa>";
-    assert(xml.parsedFahrplan.array == [["direction" : "Wernerwerkstraße", "line" : "6",
+    q"[
+        <efa>
+            <dps>
+                <dp>
+                    <realtime>0</realtime>
+                    <st>
+                        <t>1224</t>
+                    </st>
+                    <m>
+                        <nu>6</nu>
+                        <des>Wernerwerkstraße</des>
+                    </m>
+                </dp>
+                <dp>
+                    <realtime>1</realtime>
+                    <st>
+                        <t>1353</t>
+                        <rt>1356</rt>
+                    </st>
+                    <m>
+                        <nu>11</nu>
+                        <des>Burgweinting</des>
+                    </m>
+                </dp>
+            </dps>
+        </efa>
+    ]".parsedFahrplan.array.shouldEqual([["direction" : "Wernerwerkstraße", "line" : "6",
             "departure" : "12:24", "delay" : "0"], ["direction" : "Burgweinting",
             "line" : "11", "departure" : "13:53", "delay" : "3"]]);
 }
@@ -104,41 +161,47 @@ body
 
 @system unittest
 {
-    import std.exception : assertThrown;
+    "<dp><st><t>0000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldEqual(TimeOfDay(0, 0));
 
-    auto xml = "<dp><st><t>0000</t></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.departureTime == TimeOfDay(0, 0));
+    "<dp><st><t>0013</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldEqual(TimeOfDay(0, 13));
 
-    xml = "<dp><st><t>0013</t></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.departureTime == TimeOfDay(0, 13));
+    "<dp><st><t>1100</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldEqual(TimeOfDay(11, 00));
 
-    xml = "<dp><st><t>1100</t></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.departureTime == TimeOfDay(11, 00));
+    "<dp><st><t>1242</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldEqual(TimeOfDay(12, 42));
 
-    xml = "<dp><st><t>1242</t></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.departureTime == TimeOfDay(12, 42));
+    "<dp><st><t>2359</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldEqual(TimeOfDay(23, 59));
 
-    xml = "<dp><st><t>2359</t></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.departureTime == TimeOfDay(23, 59));
+    "<dp><st><t>2400</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
 
-    assertThrown!DateTimeException("<dp><st><t>2400</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>0061</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>2567</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t></t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>0</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>00</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>000000</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>00:00</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
-    assertThrown!DateTimeException("<dp><st><t>abcd</t></st></dp>".readDocument.parseXPath("/dp")
-            .front.departureTime);
+    "<dp><st><t>0061</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>2567</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t></t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>0</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>00</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>000000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>00:00</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
+
+    "<dp><st><t>abcd</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.departureTime.shouldThrow!DateTimeException;
 }
 
 auto delay(XmlNode dp)
@@ -173,70 +236,59 @@ body
 
 @system unittest
 {
-    import std.exception : assertThrown;
     import core.exception : AssertError;
 
-    auto xml = "<dp><realtime>0</realtime></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(0));
+    "<dp><realtime>0</realtime></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(0));
 
-    xml = "<dp><realtime></realtime></dp>".readDocument.parseXPath("/dp").front;
-    assertThrown!(UnexpectedValueException!string)(xml.delay);
+    "<dp><realtime></realtime></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(UnexpectedValueException!string);
 
-    xml = "<dp><realtime>2</realtime></dp>".readDocument.parseXPath("/dp").front;
-    assertThrown!(UnexpectedValueException!string)(xml.delay);
+    "<dp><realtime>2</realtime></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(UnexpectedValueException!string);
 
-    xml = "<dp><realtime>a</realtime></dp>".readDocument.parseXPath("/dp").front;
-    assertThrown!(UnexpectedValueException!string)(xml.delay);
+    "<dp><realtime>a</realtime></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(UnexpectedValueException!string);
 
-    xml = "<dp><realtime>1</realtime></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"seconds"(0));
+    "<dp><realtime>1</realtime></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"seconds"(0));
 
-    xml = "<dp><realtime>1</realtime><st><t></t></st></dp>".readDocument.parseXPath("/dp").front;
-    assertThrown!DateTimeException(xml.delay);
+    "<dp><realtime>1</realtime><st><t></t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(DateTimeException);
 
-    xml = "<dp><realtime>1</realtime><st><rt></rt></st></dp>".readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"seconds"(0));
+    "<dp><realtime>1</realtime><st><rt></rt></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"seconds"(0));
 
-    xml = "<dp><st><rt></rt><t></t></st></dp>".readDocument.parseXPath("/dp").front;
-    assertThrown!AssertError(xml.delay);
+    "<dp><st><rt></rt><t></t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(AssertError);
 
-    xml = "<dp><realtime>1</realtime><st><rt></rt><t></t></st></dp>".readDocument.parseXPath("/dp")
-        .front;
-    assertThrown!DateTimeException(xml.delay);
+    "<dp><realtime>1</realtime><st><rt></rt><t></t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(DateTimeException);
 
-    xml = "<dp><realtime>1</realtime><st><rt>0000</rt><t></t></st></dp>".readDocument.parseXPath("/dp")
-        .front;
-    assertThrown!DateTimeException(xml.delay);
+    "<dp><realtime>1</realtime><st><rt>0000</rt><t></t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(DateTimeException);
 
-    xml = "<dp><realtime>1</realtime><st><rt></rt><t>0000</t></st></dp>".readDocument.parseXPath("/dp")
-        .front;
-    assertThrown!DateTimeException(xml.delay);
+    "<dp><realtime>1</realtime><st><rt></rt><t>0000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldThrow!(DateTimeException);
 
-    xml = "<dp><realtime>1</realtime><st><rt>0000</rt><t>0000</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(0));
+    "<dp><realtime>1</realtime><st><rt>0000</rt><t>0000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(0));
 
-    xml = "<dp><realtime>1</realtime><st><rt>0001</rt><t>0000</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(1));
+    "<dp><realtime>1</realtime><st><rt>0001</rt><t>0000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(1));
 
-    xml = "<dp><realtime>1</realtime><st><rt>1753</rt><t>1751</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(2));
+    "<dp><realtime>1</realtime><st><rt>1753</rt><t>1751</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(2));
 
-    xml = "<dp><realtime>1</realtime><st><rt>1010</rt><t>1000</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(10));
+    "<dp><realtime>1</realtime><st><rt>1010</rt><t>1000</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(10));
 
-    xml = "<dp><realtime>1</realtime><st><rt>1301</rt><t>1242</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(19));
+    "<dp><realtime>1</realtime><st><rt>1301</rt><t>1242</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(19));
 
-    xml = "<dp><realtime>1</realtime><st><rt>0000</rt><t>1242</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(678));
+    "<dp><realtime>1</realtime><st><rt>0000</rt><t>1242</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(678));
 
-    xml = "<dp><realtime>1</realtime><st><rt>0000</rt><t>2359</t></st></dp>"
-        .readDocument.parseXPath("/dp").front;
-    assert(xml.delay == dur!"minutes"(1));
+    "<dp><realtime>1</realtime><st><rt>0000</rt><t>2359</t></st></dp>".readDocument.parseXPath("/dp")
+        .front.delay.shouldEqual(dur!"minutes"(1));
 }
diff --git a/source/substitution.d b/source/substitution.d
index 07c239f..9575426 100644
--- a/source/substitution.d
+++ b/source/substitution.d
@@ -4,6 +4,11 @@ import std.file : slurp;
 import std.meta : AliasSeq;
 import std.traits : Parameters;
 
+version (unittest)
+{
+    import unit_threaded;
+}
+
 public:
 
 /***********************************
@@ -30,7 +35,7 @@ void loadSubstitutionFile(alias slurpFun = slurp)(string fileName)
     }
 
     loadSubstitutionFile!mockSlurpEmpty("");
-    assert(map.length == 0);
+    map.length.shouldEqual(0);
 
     static Tuple!(string, string)[] mockSlurpEmptyEntry(Type1, Type2)(string filename,
             in char[] format)
@@ -39,9 +44,9 @@ void loadSubstitutionFile(alias slurpFun = slurp)(string fileName)
     }
 
     loadSubstitutionFile!mockSlurpEmptyEntry("");
-    assert("" in map);
-    assert(map.length == 1);
-    assert(map[""] == "");
+    "".shouldBeIn(map);
+    map.length.shouldEqual(1);
+    map[""].shouldEqual("");
 
     static Tuple!(string, string)[] mockSlurpSingleEntry(Type1, Type2)(string filename,
             in char[] format)
@@ -50,9 +55,9 @@ void loadSubstitutionFile(alias slurpFun = slurp)(string fileName)
     }
 
     loadSubstitutionFile!mockSlurpSingleEntry("");
-    assert("foo" in map);
-    assert(map.length == 1);
-    assert(map["foo"] == "bar");
+    "foo".shouldBeIn(map);
+    map.length.shouldEqual(1);
+    map["foo"].shouldEqual("bar");
 
     static Tuple!(string, string)[] mockSlurpMultipleEntries(Type1, Type2)(
             string filename, in char[] format)
@@ -61,13 +66,13 @@ void loadSubstitutionFile(alias slurpFun = slurp)(string fileName)
     }
 
     loadSubstitutionFile!mockSlurpMultipleEntries("");
-    assert("" in map);
-    assert("0" in map);
-    assert("Text in" in map);
-    assert(map.length == 3);
-    assert(map[""] == "");
-    assert(map["0"] == "1");
-    assert(map["Text in"] == "wird durch diesen ersetzt");
+    "".shouldBeIn(map);
+    "0".shouldBeIn(map);
+    "Text in".shouldBeIn(map);
+    map.length.shouldEqual(3);
+    map[""].shouldEqual("");
+    map["0"].shouldEqual("1");
+    map["Text in"].shouldEqual("wird durch diesen ersetzt");
 }
 
 /***********************************
@@ -84,20 +89,20 @@ auto substitute(string s) @safe nothrow
 @safe unittest
 {
     map[""] = "";
-    assert(substitute("") == "");
+    "".substitute.shouldEqual("");
 
     map["a"] = "b";
-    assert(substitute("a") == "b");
+    "a".substitute.shouldEqual("b");
 
     map["Regensburg Danziger Freiheit"] = "Danziger Freiheit";
-    assert(substitute("Regensburg Danziger Freiheit") == "Danziger Freiheit");
+    "Regensburg Danziger Freiheit".substitute.shouldEqual("Danziger Freiheit");
 
     map["Regensburg Danziger Freiheit"] = "Anderer Test";
-    assert(substitute("Regensburg Danziger Freiheit") == "Anderer Test");
+    "Regensburg Danziger Freiheit".substitute.shouldEqual("Anderer Test");
 
-    assert(substitute("z") == "z");
+    "z".substitute.shouldEqual("z");
 
-    assert(substitute("Regensburg Hauptbahnhof") == "Regensburg Hauptbahnhof");
+    "Regensburg Hauptbahnhof".substitute.shouldEqual("Regensburg Hauptbahnhof");
 }
 
 private: