PromptAssert

NexusLabs.Needlr.AgentFramework.Testing

PromptAssert Class

Assertion helpers for verifying prompt integrity without LLM invocation. Use in unit tests to catch prompt regressions (missing safety rules, deleted sections, forbidden patterns) at zero token cost.

public static class PromptAssert

Inheritance System.Object 🡒 PromptAssert

Example

[Fact]
public void WriterPrompt_HasSafetyRules()
{
    PromptAssert.Contains(WriterPrompt.Text, "ABSOLUTE RULE");
    PromptAssert.ContainsInSection(WriterPrompt.Text, "### Critical", "meta-instruction-leak");
    PromptAssert.ForbidsPattern(WriterPrompt.Text, @"TODO|FIXME|HACK");
}

Methods

PromptAssert.Contains(string, string) Method

Asserts that prompt contains expected using System.StringComparison.OrdinalIgnoreCase.

public static void Contains(string prompt, string expected);

Parameters

prompt System.String

The prompt text to inspect.

expected System.String

The substring that must be present.

Exceptions

System.ArgumentException
prompt is null or expected is null or empty.

PromptAssertionException
The expected text was not found.

PromptAssert.Contains(string, string, StringComparison) Method

Asserts that prompt contains expected using the specified comparison.

public static void Contains(string prompt, string expected, System.StringComparison comparison);

Parameters

prompt System.String

The prompt text to inspect.

expected System.String

The substring that must be present.

comparison System.StringComparison

The comparison rule to use.

Exceptions

System.ArgumentException
prompt is null or expected is null or empty.

PromptAssertionException
The expected text was not found.

PromptAssert.ContainsInSection(string, string, string) Method

Asserts that expected appears within the markdown section that starts at sectionHeader. The section ends at the next header of equal or higher level, or at the end of the prompt.

public static void ContainsInSection(string prompt, string sectionHeader, string expected);

Parameters

prompt System.String

The prompt text to inspect.

sectionHeader System.String

The markdown header that starts the section (e.g., "### Critical").

expected System.String

The text that must appear inside the section.

Exceptions

System.ArgumentException
prompt is null or sectionHeader or expected is null or empty.

PromptAssertionException
The section was not found, or the expected text was not in the section.

PromptAssert.DoesNotContain(string, string) Method

Asserts that prompt does NOT contain forbidden using System.StringComparison.OrdinalIgnoreCase.

public static void DoesNotContain(string prompt, string forbidden);

Parameters

prompt System.String

The prompt text to inspect.

forbidden System.String

The substring that must be absent.

Exceptions

System.ArgumentException
prompt is null or forbidden is null or empty.

PromptAssertionException
The forbidden text was found.

PromptAssert.ForbidsPattern(string, string) Method

Asserts that prompt does not match regexPattern.

public static void ForbidsPattern(string prompt, string regexPattern);

Parameters

prompt System.String

The prompt text to inspect.

regexPattern System.String

A regular expression pattern that must NOT match.

Exceptions

System.ArgumentException
prompt is null or regexPattern is null or empty.

PromptAssertionException
The pattern matched.

PromptAssert.HasSection(string, string) Method

Asserts that prompt contains a markdown section header matching sectionHeader (e.g., "### Critical").

public static void HasSection(string prompt, string sectionHeader);

Parameters

prompt System.String

The prompt text to inspect.

sectionHeader System.String

The markdown header text (including # prefix).

Exceptions

System.ArgumentException
prompt is null or sectionHeader is null or empty.

PromptAssertionException
The section header was not found.

PromptAssert.SectionOrder(string, string, string) Method

Asserts that firstSection appears before secondSection in prompt.

public static void SectionOrder(string prompt, string firstSection, string secondSection);

Parameters

prompt System.String

The prompt text to inspect.

firstSection System.String

The section header that should come first.

secondSection System.String

The section header that should come second.

Exceptions

System.ArgumentException
prompt is null or firstSection or secondSection is null or empty.

PromptAssertionException
A section was not found, or the order was reversed.