/// <summary>
/// 构造函数
/// </summary>
/// <param name="variableCoercisonStrategy">默认变量值约束策略</param>
/// <param name="context">公式执行上下文</param>
public CSharpFormulaGlobal(
IVariableCoercionStrategy variableCoercisonStrategy,
FormulaEvaluatingContext context)
{
this.variableCoercisonStrategy = variableCoercisonStrategy;
this.context = context;
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="formula">表达式</param>
/// <param name="context">执行上下文</param>
/// <returns></returns>
public async Task <double> EvalAsync(string formula, FormulaEvaluatingContext context)
{
try
{
double result = await CSharpScript.EvaluateAsync <double>(
formula,
ScriptOptions.Default
//.WithImports("System")
.WithImports(availableMethodsType.Namespace)
.WithReferences(
typeof(System.Math).Assembly,
typeof(System.Double).Assembly,
typeof(Nullable <>).Assembly,
typeof(CSharpFormulaGlobal).Assembly,
availableMethodsType.Assembly
),
new CSharpFormulaGlobal(variableCoercisonStrategy, context)
);
if (Double.IsInfinity(result))
{
throw new DivideByZeroException($"公式 {formula} 发生除数为零异常");
}
return(result);
}
catch (CompilationErrorException e)
when(e.Message.Contains("CS0020"))
{
throw new DivideByZeroException($"公式 {formula} 发生除数为零异常");
}
}
public async Task DoubleThrowWhenEvalDivideByZeroTest()
{
var evaluator = new CSharpExecutor(typeof(Math), new NullNotAllowedStrategy());
var fakeVarProvider = A.Fake <IVariableProvider>();
var context = new FormulaEvaluatingContext
{
VariableProvider = fakeVarProvider
};
var formula = "1.0/0";
await Assert.ThrowsAsync <DivideByZeroException>(() =>
evaluator.EvalAsync(formula, context)
);
}
public async Task EvalNonExistingVariableTest()
{
var evaluator = new CSharpExecutor(typeof(Math), new NullNotAllowedStrategy());
var fakeVarProvider = A.Fake <IVariableProvider>();
A.CallTo(() => fakeVarProvider.GetVarAsync("a"))
.Returns(Task.FromResult <double?>(null));
var context = new FormulaEvaluatingContext
{
VariableProvider = fakeVarProvider
};
var formula = "await Var(\"a\") + await Var(\"b\") + 3";
await Assert.ThrowsAsync <CoerceVariableFailException>(() =>
evaluator.EvalAsync(formula, context)
);
}
public async Task IntThrowWhenEvalDivideByZeroTest()
{
var evaluator = new CSharpExecutor(typeof(Math), new NullNotAllowedStrategy());
var fakeVarProvider = A.Fake <IVariableProvider>();
A.CallTo(() => fakeVarProvider.GetVarAsync("a"))
.Returns(0);
var context = new FormulaEvaluatingContext
{
VariableProvider = fakeVarProvider
};
var formula = "1/await Var(\"a\")";
await Assert.ThrowsAsync <DivideByZeroException>(() =>
evaluator.EvalAsync(formula, context)
);
}
public async Task EvalExpressionTest(string formula, double expected)
{
//var evaluator = new CSharpExecutor(new NullNotAllowedStrategy());
//var fakeVarProvider = A.Fake<IVariableProvider>();
//A.CallTo(() => fakeVarProvider.GetVarAsync("a", A<VariableCriteria>.That.IsNotNull()))
// .Returns(10);
//A.CallTo(() => fakeVarProvider.GetVarAsync("参数", A<VariableCriteria>.That.IsNotNull()))
// .Returns(20);
//A.CallTo(() => fakeVarProvider.GetVarAsync("PI", A<VariableCriteria>.That.IsNotNull()))
// .Returns(Math.PI);
//var context = new FormulaEvaluatingContext
//{
// VariableProvider = fakeVarProvider,
// DistrictIndicatorResolver = A.Fake<IDistrictIndicatorResolver>(),
//};
//var actual = await evaluator.EvalAsync(formula, context);
//Assert.Equal(expected, actual);
var evaluator = new CSharpExecutor(typeof(Math), new NullNotAllowedStrategy());
var fakeVarProvider = A.Fake <IVariableProvider>();
A.CallTo(() => fakeVarProvider.GetVarAsync("a"))
.Returns(10);
A.CallTo(() => fakeVarProvider.GetVarAsync("参数"))
.Returns(20);
A.CallTo(() => fakeVarProvider.GetVarAsync("PI"))
.Returns(Math.PI);
var context = new FormulaEvaluatingContext
{
VariableProvider = fakeVarProvider,
//DistrictIndicatorResolver = A.Fake<IDistrictIndicatorResolver>(),
};
var actual = await evaluator.EvalAsync(formula, context);
Assert.Equal(expected, actual);
}
/// <summary>
/// 执行表达式
/// </summary>
/// <param name="formula">表达式</param>
/// <param name="context">执行上下文</param>
/// <returns></returns>
public Task <double> EvalAsync(string formula, FormulaEvaluatingContext context)
{
var scriptToExecute = interpreter.Interpret(formula, availableMethodsType);
return(executor.EvalAsync(scriptToExecute, context));
}
/// <summary>
/// 从变量源获取原始值
/// </summary>
/// <param name="variableName"></param>
/// <param name="context"></param>
/// <returns></returns>
private async Task <double?> GetRawValue(string variableName, FormulaEvaluatingContext context)
{
return(await context.VariableProvider.GetVarAsync(variableName));
}
