Add unit tests

build-and-test.ps1

@@ -0,0 +1,2 @@
+.\build.ps1
+.\test.ps1

src/Classes/Assert.cls

@@ -0,0 +1,45 @@
+VERSION 1.0 CLASS
+BEGIN
+  MultiUse = -1  'True
+END
+Attribute VB_Name = "Assert"
+Attribute VB_GlobalNameSpace = False
+Attribute VB_Creatable = False
+Attribute VB_PredeclaredId = True
+Attribute VB_Exposed = True
+' Indicates whether the assertion was successful
+Public AssertSuccessful As Boolean
+' The message of this assertion
+Public AssertMessage As String
+
+
+' Asserts that both values are equal. If not, this will return a failed assertion.
+' Arguments:
+' - expected The value the caller expects to have
+' - actual The actual value
+' - message A message to show in case the assertion failed
+Public Function AreEqual(ByRef expected, ByRef actual, ByRef message As String) As Assert
+        Set AreEqual = IsTrue(Not expected <> actual, message)
+
+        If Not AreEqual.AssertSuccessful Then
+            AreEqual.AssertMessage = AreEqual.AssertMessage & vbCrLf & "    Expected: " & expected & vbCrLf & "    Actual:   " & actual
+        End If
+End Function
+
+
+' Asserts that the given value is true.
+' Arguments:
+' - truthy A value that can be seen as truthy. Very likely should be boolean, but maybe you like to live dangerously
+' - message A message to show in case the assertion failed
+Public Function IsTrue(ByRef truthy, ByRef message As String) As Assert
+    Set IsTrue = New Assert
+    IsTrue.AssertSuccessful = True
+    IsTrue.AssertMessage = message
+
+    If Not truthy Then
+        IsTrue.AssertSuccessful = False
+        IsTrue.AssertMessage = "  Assert failed: " & message
+    End If
+End Function
+
+

src/Modules/Marshal.bas

@@ -3,16 +3,25 @@ Private Const integer0xFF As Integer = 256
 Private Const long0xFF As Long = 256
 
 
+' Converts the given int8 to a big endian byte string.
+' Arguments:
+' - value The byte to convert
 Public Function Int8ToBytes(ByVal value As Byte) As String
     Int8ToBytes = Chr(value)
 End Function
 
 
+' Converts the given big endian byte string to an int8
+' Arguments:
+' - bytes The bytes to convert
 Public Function BytesToInt8(ByVal bytes As String) As Byte
     BytesToInt8 = Asc(CharAt(bytes, 1))
 End Function
 
 
+' Converts the given int16 to a big endian byte string.
+' Arguments:
+' - value The byte to convert
 Public Function Int16ToBytes(ByVal value As Integer) As String
     Dim bytes As String * 2
     Dim rest As Integer
@@ -28,11 +37,17 @@ Public Function Int16ToBytes(ByVal value As Integer) As String
 End Function
 
 
+' Converts the given big endian byte string to an int16
+' Arguments:
+' - bytes The bytes to convert
 Public Function BytesToInt16(ByVal bytes As String) As Long
     BytesToInt16 = Asc(CharAt(bytes, 1)) * long0xFF + Asc(CharAt(bytes, 2))
 End Function
 
 
+' Converts the given int32 to a big endian byte string.
+' Arguments:
+' - value The byte to convert
 Public Function Int32ToBytes(ByVal value As Long) As String
     Dim bytes As String * 4
     Dim rest As Long
@@ -56,6 +71,9 @@ Public Function Int32ToBytes(ByVal value As Long) As String
 End Function
 
 
+' Converts the given big endian byte string to an int32
+' Arguments:
+' - bytes The bytes to convert
 Public Function BytesToInt32(ByVal bytes As String) As Long
     BytesToInt32 = Asc(CharAt(bytes, 1)) * long0xFF * long0xFF * long0xFF + Asc(CharAt(bytes, 2)) * long0xFF * long0xFF + Asc(CharAt(bytes, 3)) * long0xFF + Asc(CharAt(bytes, 4))
 End Function

src/Modules/StringExtensions.bas

@@ -1,5 +1,9 @@
 Attribute VB_Name = "StringExtensions"
-Public Function TrimLeft(text As String, c As String) As String
+' Trims the given character from the given text starting from the left.
+' Arguments:
+' - text The text to trim
+' - c The character to trim
+Public Function TrimLeft(ByVal text As String, c As String) As String
     Dim textLength As Long
     textLength = Len(text)
 
@@ -20,7 +24,11 @@ Public Function TrimLeft(text As String, c As String) As String
 End Function
 
 
-Public Function TrimRight(text As String, c As String) As String
+' Trims the given character from the given text starting from the right.
+' Arguments:
+' - text The text to trim
+' - c The character to trim
+Public Function TrimRight(ByVal text As String, c As String) As String
     Dim textLength As Long
     textLength = Len(text)
 
@@ -41,34 +49,59 @@ Public Function TrimRight(text As String, c As String) As String
 End Function
 
 
-Public Function Substring(ByVal text As String, startIndex As Integer, Optional length As Variant) As String
+' Gets the substring from the given text.
+' Arguments:
+' - text The text to get the substring from
+' - startIndex The index of the first character of the substring
+' - [length] The amount of characters to take from the original string
+Public Function Substring(ByVal text As String, ByVal startIndex As Integer, Optional ByVal length As Variant) As String
     If startIndex > Len(text) Then
         startIndex = Len(text)
     End If
 
-    If IsMissing(length) Or TypeName(length) <> "Integer" Or length > Len(text) Then
+    If IsMissing(length) Then
+        length = Len(text) - startIndex
+    End If
+
+    If length > Len(text) Then
         length = Len(text) - startIndex
     End If
 
     Substring = Left(Right(text, Len(text) - startIndex), length)
 End Function
 
 
+' Checks whether the given text starts with the given sequence.
+' Arguments:
+' - text The text to check for the sequence
+' - startText The text to be located at the start
 Public Function StartsWith(ByVal text As String, ByVal startText As String) As Boolean
     StartsWith = InStr(text, startText) = 1
 End Function
 
 
+' Checks whether the given text ends with the given sequence.
+' Arguments:
+' - text The text to check for the sequence
+' - endText The text to be located at the end
 Public Function EndsWith(ByVal text As String, ByVal endText As String) As Boolean
     EndsWith = Right(text, Len(endText)) = endText
 End Function
 
 
+' Gets the character at the given index from the given string.
+' Arguments:
+' - text The text to get the character from
+' - index The index of the character to get
 Public Function CharAt(ByVal text As String, ByVal index As Integer) As String
     CharAt = Mid(text, index, 1)
 End Function
 
 
+' Repeats the given string the given amount of times.
+' Arguments:
+' - text The text to repeat
+' - count The amount of times to repeat the given string
 Public Function Repeat(ByVal text As String, ByVal count As Long) As String
     Repeat = ""
 
@@ -77,3 +110,11 @@ Public Function Repeat(ByVal text As String, ByVal count As Long) As String
         Repeat = Repeat & text
     Next
 End Function
+
+
+' Converts a regular string "foo" to a L"foo" string.
+' Arguments:
+' - text The string to convert
+Public Function StringToWideString(ByVal text As String) As String
+    StringToWideString = StrConv(text, vbUnicode)
+End Function

src/Modules/TestMarshal.bas

@@ -0,0 +1,21 @@
+Attribute VB_Name = "TestMarshal"
+Public Function TestMarshalInt8() As Assert
+    Dim value As Byte
+    value = 10
+
+    Set TestMarshalInt8 = Assert.AreEqual(value, Marshal.BytesToInt8(Marshal.Int8ToBytes(value)), "marshals int8")
+End Function
+
+Public Function TestMarshalInt16() As Assert
+    Dim value As Long
+    value = 10
+
+    Set TestMarshalInt16 = Assert.AreEqual(value, Marshal.BytesToInt16(Marshal.Int16ToBytes(value)), "marshals int16")
+End Function
+
+Public Function TestMarshalInt32() As Assert
+    Dim value As Long
+    value = 10
+
+    Set TestMarshalInt32 = Assert.AreEqual(value, Marshal.BytesToInt32(Marshal.Int32ToBytes(value)), "marshals int32")
+End Function

src/Modules/TestStringExtensions.bas

@@ -0,0 +1,35 @@
+Attribute VB_Name = "TestStringExtensions"
+Public Function TestTrimLeft() As Assert
+    Set TestTrimLeft = Assert.AreEqual("bar", StringExtensions.TrimLeft("oobar", "o"), "left-trims strings")
+End Function
+
+
+Public Function TestTrimRight() As Assert
+    Set TestTrimRight = Assert.AreEqual("f", StringExtensions.TrimRight("foo", "o"), "right-trims strings")
+End Function
+
+
+Public Function TestStartsWith() As Assert
+    Set TestStartsWith = Assert.IsTrue(StringExtensions.StartsWith("foobar", "foo"), "detects string starts")
+End Function
+
+
+Public Function TestEndsWith() As Assert
+    Set TestEndsWith = Assert.IsTrue(StringExtensions.EndsWith("foobar", "bar"), "detects string ends")
+End Function
+
+
+Public Function TestCharAt() As Assert
+    Set TestCharAt = Assert.AreEqual("a", StringExtensions.CharAt("foobar", 5), "gets chars from strings")
+End Function
+
+
+Public Function TestSubstring() As Assert
+    Set TestSubstring = Assert.AreEqual("oo", StringExtensions.Substring("foobar", 1, 2), "gets parts from strings")
+End Function
+
+
+Public Function TestRepeat() As Assert
+    Set TestRepeat = Assert.AreEqual("aaa", StringExtensions.Repeat("a", 3), "repeats strings")
+End Function
+

src/Modules/TestUtils.bas

@@ -0,0 +1,25 @@
+Attribute VB_Name = "TestUtils"
+Public Type TestFileHandle
+    TestFilename As String
+    TestFilestream As Variant
+End Type
+
+' Creates a temporary test file.
+Public Function CreateTestFile() As TestFileHandle
+    Dim fso
+    Set fso = CreateObject("Scripting.FileSystemObject")
+
+    CreateTestFile.TestFilename = fso.BuildPath(ActiveDocument.Path, fso.GetTempName())
+    Set CreateTestFile.TestFilestream = fso.CreateTextFile(CreateTestFile.TestFilename, True)
+End Function
+
+
+' Deletes the given test file.
+' Arguments:
+' - fileHandle The file handle to delete
+Public Sub DeleteTestFile(ByRef fileHandle As TestFileHandle)
+    Dim fso
+    Set fso = CreateObject("Scripting.FileSystemObject")
+
+    fso.DeleteFile fileHandle.TestFilename
+End Sub