sean-m
/
McRule
mirror of https://github.com/sean-m/McRule.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Made nullable type checks more understandable as they only apply to value types boxed as nullables and unified return semantics for values processed as strings.

sean-m-patch-1
Sean McArde 2023-09-11 12:32:56 -07:00
parent aef5190f3e
commit 54ba5be48a
1 changed files with 17 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
McRule/PredicateExpressionPolicyExtensions.cs
View File

@ -1,4 +1,5 @@
using System.Collections;
using System;
using System.Collections;
using System.Diagnostics.Contracts;
using System.Linq.Expressions;
using System.Reflection;
@ -291,15 +292,15 @@ public abstract class ExpressionGeneratorBase : ExpressionGenerator
// Note, a float on the right hand side will not parse into an integer type implicitly
// so it is parsed into a decimal value first and then rounded to the nearest integral.
var lType = opLeft.Type;
var isNullable = false;
var isNullableValueType = false;
Type? hasComparable = lType.GetInterface("IComparable");
Type? hasCollection = lType.GetInterface("ICollection");
if (hasComparable == null && opLeft.Type.IsValueType) {
if (hasComparable == null && lType.IsValueType) {
lType = Nullable.GetUnderlyingType(opLeft.Type);
// Nullable.GetUnderlyingType only returns a non-null value if the
// supplied type was indeed a nullable type.
if (lType != null)
isNullable = true;
isNullableValueType = true;
hasComparable = lType.GetInterface("IComparable");
}
@ -313,8 +314,6 @@ public abstract class ExpressionGeneratorBase : ExpressionGenerator
// For string comparisons using wildcards, trim the wildcard characters and pass to the comparison method
if (lType == typeof(string))
{
Expression<Func<T, bool>> result;
// Grab the object property for use in the inner expression body
var strParam = Expression.Lambda<Func<T, string>>(opLeft, parameter);
@ -339,27 +338,26 @@ public abstract class ExpressionGeneratorBase : ExpressionGenerator
if (value.StartsWith("*") && value.EndsWith("*"))
{
result = AddStringPropertyExpression<T>(strParam, value.Trim('*'), "Contains", ignoreCase);
comparison = AddStringPropertyExpression<T>(strParam, value.Trim('*'), "Contains", ignoreCase);
}
else if (value.StartsWith("*"))
{
result = AddStringPropertyExpression<T>(strParam, value.TrimStart('*'), "EndsWith", ignoreCase);
comparison = AddStringPropertyExpression<T>(strParam, value.TrimStart('*'), "EndsWith", ignoreCase);
}
else if (value.EndsWith("*"))
{
result = AddStringPropertyExpression<T>(strParam, value.TrimEnd('*'), "StartsWith", ignoreCase);
comparison = AddStringPropertyExpression<T>(strParam, value.TrimEnd('*'), "StartsWith", ignoreCase);
}
else
{
result = AddStringPropertyExpression<T>(strParam, value, "Equals", ignoreCase);
comparison = AddStringPropertyExpression<T>(strParam, value, "Equals", ignoreCase);
}
if (negateResult)
{
result = Negate<T>(result);
comparison = Negate<T>((Expression<Func<T,bool>>)comparison);
}
return result;
}
else if (hasComparable == typeof(IComparable))
{
@ -377,7 +375,7 @@ public abstract class ExpressionGeneratorBase : ExpressionGenerator
var opRightNumerical = parseMethod?.Invoke(null, new string[] { operand });
opRight = Expression.Constant(opRightNumerical);
Expression opLeftFinal = isNullable ? Expression.Convert(opLeft, lType) : opLeft;
Expression opLeftFinal = isNullableValueType ? Expression.Convert(opLeft, lType) : opLeft;
comparison = GetComparer(operatorPrefix.Value.Trim(), opLeftFinal, opRight);
}
}
@ -394,11 +392,16 @@ public abstract class ExpressionGeneratorBase : ExpressionGenerator
// expression for it so just defer to a false literal.
Expression<Func<T, bool>> falsePredicate = x => false;
comparison = comparison == null ? falsePredicate : comparison;
if (isNullable)
if (isNullableValueType)
{
comparison = AddNotNullCheck<T>(opLeft, comparison);
}
// The value may have the right type and should just be returned.
if (comparison is Expression<Func<T, bool>> result) {
return result;
}
return Expression.Lambda<Func<T, bool>>(comparison ?? Expression.Equal(opLeft, opRight), parameter);
}