' Gambas module file

''' This module extends the Assert instruction, which checks
''' that Expression is TRUE, and if the Expression is FALSE,
''' an uncatchable "Assertion failed" error is raised, the
''' PRINT or ERROR instruction is executed, and the program stops immediately.

Export

Public _IntendedFailure As Boolean

Private $aIgnore As String[] = ["Assert", "Test", "TestCase", "TestSuite", "TapPrinter"]

'' Assert that Result = True
Public Sub Ok(Result As Boolean, Optional Description As String) As Boolean

    Dim bRes As Boolean
    Dim bt As String[]
    Dim sStack As String
    Dim iPos As Integer

    If Test._InSetup = True Then
        Test.BailOut(("Failure: Assertion forbidden inside _Setup or _Teardown."))
    Endif

    If _IntendedFailure Then Result = Not Result
    _IntendedFailure = False

    bt = System.Backtrace
    
    ' While bt[0] Begins "Assert." Or bt[0] Begins "Test." Or bt[0] Begins "TestCase." Or bt[0] Begins "TestSuite." Or bt[0] Begins "TapPrinter."
    '     bt.Remove(0)
    '     If bt.Count = 0 Then
    '         Goto DAWAI
    '     Endif
    ' Wend

    While bt.Count
        sStack = bt[0]
        If sStack Like "[[]*].*" Then sStack = Mid$(sStack, InStr(sStack, "]") + 2)
        iPos = InStr(sStack, ".")
        If iPos Then sStack = Left(sStack, iPos - 1)
        If Not $aIgnore.Exist(sStack) Then Break
        bt.Remove(0)
    Wend
    
DAWAI:
    If bt.Count > 0 Then
        Test._Next.Line = bt[0]
    Endif

    Test._Next.Ok = Result
    Test._Next.Description = Description
    bRes = Test._Printer.Assert(Test._Next).Ok
    Test._Next = New TestAssertion
    Return bRes

End

' -------------------- High-level test functions --------------------
'' Assert that a test is passed. Reports Ok
Public Sub Pass(Optional Description As String) As Boolean

    Return Ok(True, Description)

End

'' Assert fail. Reports not ok.
Public Sub Fail(Optional Description As String) As Boolean

    Return Ok(False, Description)

End

'' Assert that Result = False.
Public Sub NotOk(Result As Boolean, Optional Description As String) As Boolean

    Return Ok(Not Result, Description)

End

'' Assert that Got = Expected
Public Sub Equals(Got As Variant, Expected As Variant, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got = Expected, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Expected)
    Endif
    Return bRes

End

'' Assert that Got <> Expected
Public Sub Notequals(Got As Variant, UnExpected As Variant, Optional Description As String) As Boolean

    Return Ok(Got <> UnExpected, Description)

End

'' Assert that Got <= Bound
Public Sub LessEqual(Got As Variant, Bound As Variant, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got <= Bound, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Bound)
    Endif
    Return bRes

End

'' Assert that Got < Bound
Public Sub Less(Got As Variant, Bound As Variant, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got < Bound, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Bound)
    Endif
    Return bRes

End

'' Assert that Got >= Bound
Public Sub GreaterEqual(Got As Variant, Bound As Variant, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got >= Bound, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Bound)
    Endif
    Return bRes

End

'' Assert that Got > Bound
Public Sub Greater(Got As Variant, Bound As Variant, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got > Bound, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Bound)
    Endif
    Return bRes

End

'' Asserts that _Got_ has an [absolute error](https://en.wikipedia.org/wiki/Approximation_error) to _Expected_ of at most _Precision_.
Public Sub Approximate(Got As Float, Expected As Float, Precision As Float, Optional Description As String) As Boolean

    Dim bRes As Boolean
    Dim fAbsError As Float

    fAbsError = Abs(Got - Expected)
    bRes = Ok(fAbsError <= Precision, Description)
    If Not bRes Then
        Test.Note(Null)
        Test.Note(Subst$(("------------- Expected -------------" & gb.lf & "AbsError(&1, &2) <= &3"), Got, Expected, Precision))
        Test.Note(Null)
        Test.Note(Subst$(("---------------- Got ---------------" & gb.lf & "Got = &1" & gb.lf & "Expected = &2" & gb.lf & "|Got - Expected| = &3"), Got, Expected, fAbsError))
        Test.Note("------------------------------------")
        Test.Note(Null)
    Endif
    Return bRes

End

'' Asserts that ~Got~ has a [relative error](https://en.wikipedia.org/wiki/Approximation_error) to ~Expected~ of at most ~RelPrecision~.
'' ~Expected~ may not be zero, unless ~Got~ is also zero in which case the test succeeds.
Public Sub RelativeApproximate(Got As Float, Expected As Float, RelPrecision As Float, Optional Description As String) As Boolean

    Dim bRes As Boolean
    Dim fRelError As Float

    If Abs(Expected) = 0.0 Then
        bRes = Ok(Abs(Got) = 0.0, Description)
        Test.Note(("Expected value in RelativeApproximate is 0.0. Comparing value with 0.0 exactly..."))
        Return bRes
    Endif

    fRelError = Abs((Got - Expected) / Expected)
    bRes = Ok(fRelError <= RelPrecision)
    If Not bRes Then
        Test.Note(Null)
        Test.Note(Subst$(("------------- Expected -------------" & gb.lf & "RelError(&1, &2) <= &3"), Got, Expected, RelPrecision))
        Test.Note(Null)
        Test.Note(Subst$(("---------------- Got ---------------" & gb.lf & "Got = &1" & gb.lf & "Expected = &2" & gb.lf & "|Got - Expected|/|Expected| = &3"), Got, Expected, fRelError))
        Test.Note("------------------------------------")
        Test.Note(Null)
    Endif
    Return bRes

End

'' Assert that Got is of the type Type
Public Sub IsType(Got As Variant, Type As Integer, Optional Description As String) As Boolean

    Return Equals(TypeOf(Got), Type, Description)

End

'' Assert that Got = Null
Public Sub Null(Got As Variant, Optional Description As String) As Boolean

    Return Equals(Got, Null, Description)

End

'' Assert that Got <> Null
Public Sub NotNull(Got As Variant, Optional Description As String) As Boolean

    Return Notequals(Got, Null, Description)

End

'' Assert that Got Like Pattern. See also the Like string operator.
Public Sub Like(Got As String, Pattern As String, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got Like Pattern, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Pattern)
    Endif
    Return bRes

End

'' Assert that Got Match Pattern. See also the Match string operator.
Public Sub Match(Got As String, Pattern As String, Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Got Match Pattern, Description)
    If Not bRes Then
        NoteGotAndExpected(Got, Pattern)
    Endif
    Return bRes

End

'' Assert that Got = Expected. On failure reports hints about the difference.
Public Sub StringEquals(Got As String, Expected As String, Optional Description As String) As Boolean

    Dim bRes As Boolean
    Dim iPos As Integer

    bRes = Equals(Got, Expected, Description)
    If Not bRes Then
        If Len(Got) <> Len(Expected) Then
            Test.Note(Subst$(("Strings are of different lengths &1 and &2, respectively."), Len(Got), Len(Expected)))
        Endif
        For iPos = 1 To Min(Len(Got), Len(Expected))
            If Mid$(Got, iPos, 1) <> Mid$(Expected, iPos, 1) Then Break
        Next
        Test.Note(Subst$(("Strings differ at position &1."), iPos))
    Endif
    Return bRes

End

'' Assert that an error happened. Reports not ok if no error happened.
''
'' Example:
'' Try 2/0
'' Assert.Error("division by zero")
Public Sub Error(Optional Description As String) As Boolean

    Return Ok(Error, Description)

End

'' Assert that an error happened with error code. Reports not ok
'' if no error happend or if the error code is wrong.
''
'' Example:
'' Try Print 2 / 0
'' Assert.ErrorCode(26, "division by zero with code 26")
Public Sub ErrorCode(Code As Integer, Optional Description As String) As Boolean

    Dim bRes As Boolean

    If Not Error Then
        bRes = Fail(Description)
        Test.Note(("No error happened"))
    Else
        bRes = Equals(Error.Code, Code, Description)
        If Not bRes Then
            Test.Note(Subst$(("Error was: &1 (code: &2) at &3"), Error.Text, Error.Code, Error.Where))
        Endif
    Endif

    Error.Clear()
    Return bRes

End

'' Assert that no error happened.
''
''Example:
''
''Try Print 2 / 2
''Assert.Noterror("Division ok")
Public Sub Noterror(Optional Description As String) As Boolean

    Dim bRes As Boolean

    bRes = Ok(Not Error, Description)
    If Not bRes Then
        Test.Note(Subst$(("Error was: &1 (code: &2) at &3"), Error.Text, Error.Code, Error.Where))
    Endif

    Error.Clear()
    Return bRes

End

' ------------------------------------------------- Helper functions

Private Sub NoteGotAndExpected(Got As String, Expected As String)

    Test.Note(Null)
    Test.Note(Subst$(("------------- Expected -------------" & gb.lf & "&1"), Expected))
    Test.Note(Null)
    Test.Note(Subst$(("---------------- Got ---------------" & gb.lf & "&1"), Got))
    Test.Note("------------------------------------")
    Test.Note(Null)

End
