BizTalk Server Mapping Error: Inline Script Error: Invalid expression term ‘)’

Oh yes! I’m back to one of my favorite topics: Errors and warnings, causes and solutions – aka Troubleshooting! This time, I’m combining two things I like: mapping and BizTalk Server. What could go wrong!

While trying to implement a mapping rule using C# inline code, where the goal was to infer the conversion rate between two coins: EUR to any other coin. This was the code I have used (courtesy of ChatGPT)

public static string EurPerCoin(string eurAmount, string coinAmount)
{
        if (!decimal.TryParse(eurAmount, NumberStyles.Number, CultureInfo.InvariantCulture, out var eur))
            return "0.00";

        if (!decimal.TryParse(coinAmount, NumberStyles.Number, CultureInfo.InvariantCulture, out var coin))
            return "0.00";

        if (coin == 0)
            return "0.00";

        var rate = eur / coin;
        return Math.Round(rate, 2, MidpointRounding.AwayFromZero)
                   .ToString("F2", CultureInfo.InvariantCulture);
}

I got these two generic errors:

Error Inline Script Error: Invalid expression term ‘)’
Error Inline Script Error: ; expected

I wasn’t surprised to receive those kinds of errors because the generated code is using namespaces that are not referenced in the BizTalk Server map. So, it is always a good practice to copy your code to a Visual Studio console application and validate it

Of course, to fix this is very simple. Since we cannot use Using System.Globalization; we need to provide the full namespace in the code.

public static string EurPerCoin(string eurAmount, string coinAmount)
{
    if (!decimal.TryParse(eurAmount, System.Globalization.NumberStyles.Number, System.Globalization.CultureInfo.InvariantCulture, out var eur))
        return "0.00";

    if (!decimal.TryParse(coinAmount, System.Globalization.NumberStyles.Number, System.Globalization.CultureInfo.InvariantCulture, out var coin))
        return "0.00";

    if (coin == 0)
        return "0.00";

    var rate = eur / coin;
    return Math.Round(rate, 2, MidpointRounding.AwayFromZero).ToString("F2", System.Globalization.CultureInfo.InvariantCulture);
}

However, when I try to compile, I still encounter the exact same problems. Now I was curious.

Cause

These error messages are generic error messages and basically tell you that there is a code “interpretation” issue. And this can occur for the following reasons:

• There is a code syntax error.
  • And again, better to troubleshoot that inside a support C# console application project.
• You are using namespaces that are not included/recognized by default by the BizTalk Mapper.
  • Here, you need to provide the full namespace as we did above.
• Or you are using code not supported by the .NET 2.0 Framework, which is used inside the mapper.

In our case, for example: .NET 2.0 Framework does not support var keyword. The var keyword was introduced in C# 3.0, which shipped with .NET Framework 3.5. In .NET 2.0 (C# 2.0), you must explicitly declare the type of every variable.

Solution

The solution to this issue is quite simple: we must explicitly declare the type of every variable we use inside our C# inline code.

In our case, for example, to make the map work, we have to use the following code:

public static string EurPerCoin(string eurAmount, string coinAmount)
{
    decimal eur = 0;
    decimal coin = 0;
    if (!decimal.TryParse(eurAmount, System.Globalization.NumberStyles.Number, System.Globalization.CultureInfo.InvariantCulture, out eur))
        return "0.00";

    if (!decimal.TryParse(coinAmount, System.Globalization.NumberStyles.Number, System.Globalization.CultureInfo.InvariantCulture, out coin))
        return "0.00";

    if (coin == 0)
        return "0.00";

    decimal rate = eur / coin;
    return Math.Round(rate, 2, MidpointRounding.AwayFromZero).ToString("F2", System.Globalization.CultureInfo.InvariantCulture);
}

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Author: Sandro Pereira

Sandro Pereira lives in Portugal and works as a consultant at DevScope. In the past years, he has been working on implementing Integration scenarios both on-premises and cloud for various clients, each with different scenarios from a technical point of view, size, and criticality, using Microsoft Azure, Microsoft BizTalk Server and different technologies like AS2, EDI, RosettaNet, SAP, TIBCO etc. He is a regular blogger, international speaker, and technical reviewer of several BizTalk books all focused on Integration. He is also the author of the book “BizTalk Mapping Patterns & Best Practices”. He has been awarded MVP since 2011 for his contributions to the integration community. View all posts by Sandro Pereira