HarmonyAnalyzers

A small set of analyzers (and an even smaller set of code fixes) to assist writing Harmony patches, primarily to identify common errors such as missing attributes, typos in names, etc. Also provides autocomplete suggestions for patch method argument injections.

Completions

Completion suggestions are provided for patch method parameter injections and for the argumentTypes argument to the [HarmonyPatch] attribute.

Rules (as of v1.3)

MHA001: Missing class attribute

Methods with [HarmonyPatch] attributes in class without a [HarmonyPatch] attribute.

MHA002: Missing patch type attribute

A method with a [HarmonyPatch] patch type method attribute that is not named Postfix, Prefix, Transpiler, etc.

MHA003: Missing MethodType argument

A [HarmonyPatch] attribute without a methodType parameter and targeting a method that is not a standard method (eg. property accessor, constructor, indexer).

MHA004: Ambiguous match

A patch targeting an overloaded method and without an argumentTypes argument.

MHA005: No matching method found

No method matching the provided {HarmonyPatch} arguments was found.

MHA006: No patch methods in patch class

A class with a [HarmonyPatch] attribute and no patch methods.

MHA007: TargetMethod(s) + HarmonyPatch attribute arguments

A patch class containing [HarmonyPatch] arguments and TargetMethod or TargetMethods methods.

MHA008: Assignment to non-ref patch method argument

Assignment to a non-ref, non-out patch method argument.

MHA009: Invalid patch method return type

Patch method return type is not value for its patch type (IEnumerable<CodeInstruction> for a transpiler, void or bool for a prefix, etc.)

MHA010: [HarmonyPatch] attribute conflict

Multiple [HarmonyPatch] attributes applied to a method (and/or class) with conflicting target method arguments.

MHA011: Multiple patch type attributes on the same method

eg. HarmonyPostfix and HarmonyPrefix.

MHA012: __result injection in passthrough Postfix

An injected __result argument in a passthrough postfix method's parameters.

MHA013: No matching parameter on target method

An injected argument does not match any parameter on the target method.

MHA014: Invalid injected parameter type

The type of an injected argument does not match the type of the argument on the target method with the same name.

MHA015: Injections in transpiler patch method

Invalid injected arguments in a transpiler method.

MHA016: Use out for __state in prefix patches

An __state parameter injection in a prefix patch should be out.

MHA017: Use of indexed argument injection over parameter name

Argument injections should use the parameter names from the target method and not index (__0, __1, etc.)

MHA018: Reverse patch method signature does not match target method

Non-transpiler reverse patch signature must match the target method.

Code fixes

Fixes are provided for the following rules:

• MHA001
• MHA002
• MHA003
• MHA008
• MHA012
• MHA016
• MHA017
• MHA018

Notes

Analysis is currently not fully implemented for reverse patches and not at all for ReturnRef<T>.