change_signature

Add, remove, or reorder a method's parameters and update every call site (Roslyn's own change-signature engine). Cascades to overrides and interface implementations, rewrites named and optional arguments, and preserves an extension method's this parameter; the overrides and implementations it also rewrote are listed in CascadedTo. Operations apply in order: remove drops parameter; reorder takes order, a full permutation of the parameters surviving at that point; add appends name plus type and REQUIRES callSiteValue — the expression every existing call site will pass, since the tool never guesses call-site semantics — with an optional defaultValue that instead makes the parameter optional and leaves existing calls untouched. Rejected as unsafe: an added name that is not a valid C# identifier or collides with an existing parameter; a type that does not resolve, or resolves ambiguously (qualify it); moving or removing an extension method's this parameter (it must stay first); and any signature that would leave a surviving params array anywhere but last — add the parameter and reorder it before the params array, or remove that array. Defaults to preview mode (returns edits without writing files); set preview=false to apply. New compiler errors the change would introduce are reported as Conflicts, and apply mode refuses to write them unless force=true. Source-defined methods only; overloaded names must be disambiguated.

Parameters

Parameter	Type	Required	Description
method	string	✓	Method to change: MyClass.MyMethod or fully qualified Namespace.MyClass.MyMethod
operations	SignatureOperation[]	✓	Parameter edits applied in order. Each has kind (remove, reorder or add) plus: parameter for remove; order for reorder; name, type, callSiteValue and optional defaultValue for add
preview	bool		Preview only — return edits without writing to disk (default: true)
force	bool		Apply even when Conflicts are reported (default: false)