finding-tests

name	finding-tests
description	Locates existing tests for a given C# class and method using the test coverage data supplied by IDE. Triggers ONLY for C# production code (`.cs` files in a Rider .NET solution) when generating new tests, adding test coverage, finding existing tests, or when the user mentions uncovered lines, test files, or test suites. Must be used before writing or editing C# test code when finding already existing tests is necessary. Do NOT invoke for non-C# languages — the underlying tool only understands C# symbols and will not return useful results.
allowed-tools	execute_tool

Finding Existing Tests

Applies to: C# code only. If the production code in question is not C# - do not use this skill. Skip it silently and use the host's normal test-discovery approach. The underlying coverage tool only understands C# symbols.

Always use the findTests tool via execute_tool to locate existing tests for a given C# class and method. This tool queries the IDE code coverage data directly and is:

• Precise — returns exact test locations without false positives
• Token-efficient — no need for glob, grep, or directory listing guesses
• Fast — a single call replaces multiple rounds of searching

findTests

Find existing tests for a given production class and method. Supply the production code's class name, namespace, and file path — the tool returns the path of the single test file most relevant to the given method.

Syntax

execute_tool(command="findTests --className <value> --classNamespace <value> --filePath <value> [--methodName <value>] [--methodArguments <value>]")

Parameters

Parameter	Type	Required	Description
--className	string	Yes	Name of the class
--classNamespace	string	Yes	Namespace of the given class
--filePath	string	Yes	Absolute file path to file with the given class
--methodName	string	No	Name of the method
--methodArguments	string	No	Names and types of the method arguments — use to target a specific overload (e.g. "TextReader reader, Type objectType")

String parameters: Quote values containing spaces: --filePath '/Users/dev/MyProject/src/Services/OrderService.cs'

Examples

1. Class only — no method name

User says: "Find the tests for the JsonSerializer class"

{"tool":"execute_tool","arguments":{"command":"findTests --className JsonSerializer --classNamespace Newtonsoft.Json --filePath /projects/Newtonsoft.Json/Src/Newtonsoft.Json/JsonSerializer.cs"}}

2. With method name

User says: "Find tests for the Deserialize method in JsonSerializer"

{"tool":"execute_tool","arguments":{"command":"findTests --className JsonSerializer --classNamespace Newtonsoft.Json --filePath /projects/Newtonsoft.Json/Src/Newtonsoft.Json/JsonSerializer.cs --methodName Deserialize"}}

3. With method name and arg names — specific overload

User says: "Find tests for the Deserialize(TextReader reader, Type objectType) overload in JsonSerializer"

{"tool":"execute_tool","arguments":{"command":"findTests --className JsonSerializer --classNamespace Newtonsoft.Json --filePath /projects/Newtonsoft.Json/Src/Newtonsoft.Json/JsonSerializer.cs --methodName Deserialize --methodArguments 'TextReader reader, Type objectType'"}}

4. Generic class and method

User says: "Find tests for the ReadJson<TResult> method in JsonConverter<T>"

{"tool":"execute_tool","arguments":{"command":"findTests --className 'JsonConverter<T>' --classNamespace Newtonsoft.Json --filePath /projects/Newtonsoft.Json/Src/Newtonsoft.Json/JsonConverter.cs --methodName 'ReadJson<TResult>'"}}

5. Paths with spaces

{"tool":"execute_tool","arguments":{"command":"findTests --className DnsClient --classNamespace My.Network.Clients --filePath '/Users/dev/MyProject/src/Network Clients/DnsClient.cs' --methodName ResolveAsync"}}

Pitfalls

• Every --param MUST be followed by a value (no bare flags)
• Values with spaces must be quoted: --filePath '/Users/dev/MyProject/my folder/file.cs'
• Omit optional parameters entirely rather than passing empty strings
• All file paths must be absolute

Rules

1. C# only. Before invoking findTests, verify the production file is .cs. If it is any other language, do not invoke this skill or its tool — skip silently and fall back to standard test discovery.
2. Prefer findTests over glob, grep, or directory listing to find tests in C# code. These are wasteful and imprecise. If execute_tool is unavailable, fall back to grep/glob as a last resort and inform the user.
3. If findTests reports no tests exist, trust that result — do not retry with alternative search tools.
4. After finding tests, read them to understand the project's testing conventions before making any changes.

Troubleshooting

execute_tool not available

If execute_tool is not available, inform the user and fall back to grep/glob only as a last resort.

findTests via execute_tool timeout

If calling findTests via execute_tool times out, inform the user and fall back to your standard test discovery method. You may stop trying findTests if it timeouts for three times in a row.

No tests found

If findTests returns empty results, trust the result. Do not retry with alternative search methods.