Improve enum parsing in config binder generator

[layomia]

from @eerhardt in #88067:

Looking at your current generated code:

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

There are a couple comments here:

1. Why do we need a new method for every enum type in the graph? Can't we write 1 general "ParseEnum" method, like this one?
2. We really should use Enum.Parse<T> when possible. I did a quick benchmark:

using BenchmarkDotNet.Attributes;

namespace Benchmark;

public enum ConsoleLoggerFormat
{
    Default,
    Systemd,
}

[MemoryDiagnoser]
public class EnumParseBenchmark
{
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric() => ParseConsoleLoggerFormatGeneric("Systemd", () => "");
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormat() => ParseConsoleLoggerFormat("Systemd", () => "");

    public static ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric(string value, Func<string?> getPath)
    {
        try
        {
            return Enum.Parse<ConsoleLoggerFormat>(value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }
}

on my machine I see:

Method	Mean	Error	StdDev	Gen 0	Allocated
ParseConsoleLoggerFormatGeneric	27.92 ns	0.855 ns	0.985 ns	-	-
ParseConsoleLoggerFormat	72.91 ns	0.270 ns	0.226 ns	0.0036	24 B

The generic version is faster and doesn't allocate.

[ghost]

Tagging subscribers to this area: @dotnet/area-extensions-logging
See info in area-owners.md if you want to be subscribed.

Issue Details

---

from @eerhardt in #88067:

Looking at your current generated code:

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

There are a couple comments here:

1. Why do we need a new method for every enum type in the graph? Can't we write 1 general "ParseEnum" method, like this one?
2. We really should use Enum.Parse<T> when possible. I did a quick benchmark:

using BenchmarkDotNet.Attributes;

namespace Benchmark;

public enum ConsoleLoggerFormat
{
    Default,
    Systemd,
}

[MemoryDiagnoser]
public class EnumParseBenchmark
{
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric() => ParseConsoleLoggerFormatGeneric("Systemd", () => "");
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormat() => ParseConsoleLoggerFormat("Systemd", () => "");

    public static ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric(string value, Func<string?> getPath)
    {
        try
        {
            return Enum.Parse<ConsoleLoggerFormat>(value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }
}

on my machine I see:

Method	Mean	Error	StdDev	Gen 0	Allocated
ParseConsoleLoggerFormatGeneric	27.92 ns	0.855 ns	0.985 ns	-	-
ParseConsoleLoggerFormat	72.91 ns	0.270 ns	0.226 ns	0.0036	24 B

The generic version is faster and doesn't allocate.

Author:	layomia
Assignees:	-
Labels:	area-Extensions-Logging
Milestone:	-

[ghost]

Tagging subscribers to this area: @dotnet/area-extensions-configuration
See info in area-owners.md if you want to be subscribed.

Issue Details

---

from @eerhardt in #88067:

Looking at your current generated code:

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

There are a couple comments here:

1. Why do we need a new method for every enum type in the graph? Can't we write 1 general "ParseEnum" method, like this one?
2. We really should use Enum.Parse<T> when possible. I did a quick benchmark:

using BenchmarkDotNet.Attributes;

namespace Benchmark;

public enum ConsoleLoggerFormat
{
    Default,
    Systemd,
}

[MemoryDiagnoser]
public class EnumParseBenchmark
{
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric() => ParseConsoleLoggerFormatGeneric("Systemd", () => "");
    [Benchmark]
    public ConsoleLoggerFormat ParseConsoleLoggerFormat() => ParseConsoleLoggerFormat("Systemd", () => "");

    public static ConsoleLoggerFormat ParseConsoleLoggerFormatGeneric(string value, Func<string?> getPath)
    {
        try
        {
            return Enum.Parse<ConsoleLoggerFormat>(value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }

    public static ConsoleLoggerFormat ParseConsoleLoggerFormat(string value, Func<string?> getPath)
    {
        try
        {
            return (ConsoleLoggerFormat)Enum.Parse(typeof(ConsoleLoggerFormat), value, ignoreCase: true);
        }
        catch (Exception exception)
        {
            throw new InvalidOperationException($"Failed to convert configuration value at '{getPath()}' to type '{typeof(ConsoleLoggerFormat)}'.", exception);
        }
    }
}

on my machine I see:

Method	Mean	Error	StdDev	Gen 0	Allocated
ParseConsoleLoggerFormatGeneric	27.92 ns	0.855 ns	0.985 ns	-	-
ParseConsoleLoggerFormat	72.91 ns	0.270 ns	0.226 ns	0.0036	24 B

The generic version is faster and doesn't allocate.

Author:	layomia
Assignees:	layomia
Labels:	untriaged, area-Extensions-Configuration
Milestone:	-

[layomia]

Will keep this assigned to me; but happy to take a community contribution here.