Create errorAssertionFunction creators

To clean up table driven test with often repeated functions we can add a
simple function creator that generates a errorAssertionFunction

assert/assertions.go

@@ -48,6 +48,29 @@ type ErrorAssertionFunc func(TestingT, error, ...interface{}) bool
 // Comparison is a custom function that returns true on success and false on failure
 type Comparison func() (success bool)
 
+// ErrorIsFor returns an [ErrorAssertionFunc] which tests if the error wraps target.
+func ErrorIsFor(target error) ErrorAssertionFunc {
+	return func(t TestingT, err error, msgsAndArgs ...interface{}) bool {
+		if h, ok := t.(tHelper); ok {
+			h.Helper()
+		}
+
+		return ErrorIs(t, err, target, msgsAndArgs...)
+	}
+}
+
+// ErrorAsFor returns an [ErrorAssertionFunc] which tests if the any error in err's tree matches target and if so, assigns it to target.
+// The returned function panics if target is not a non-nil pointer to either a type that implements error, or to any interface type.
+func ErrorAsFor(target interface{}) ErrorAssertionFunc {
+	return func(t TestingT, err error, msgsAndArgs ...interface{}) bool {
+		if h, ok := t.(tHelper); ok {
+			h.Helper()
+		}
+
+		return ErrorAs(t, err, target, msgsAndArgs...)
+	}
+}
+
 /*
 	Helper functions
 */

require/requirements.go

@@ -26,4 +26,27 @@ type BoolAssertionFunc func(TestingT, bool, ...interface{})
 // for table driven tests.
 type ErrorAssertionFunc func(TestingT, error, ...interface{})
 
+// ErrorIsFunc returns an [ErrorAssertionFunc] which tests if the error wraps target.
+func ErrorIsFor(expectedError error) ErrorAssertionFunc {
+	return func(t TestingT, err error, i ...interface{}) {
+		if h, ok := t.(tHelper); ok {
+			h.Helper()
+		}
+
+		ErrorIs(t, err, expectedError, i...)
+	}
+}
+
+// ErrorAsFunc returns an [ErrorAssertionFunc] which tests if the any error in err's tree matches target and if so, assigns it to target.
+// The returned function panics if target is not a non-nil pointer to either a type that implements error, or to any interface type.
+func ErrorAsFor(expectedInterface interface{}) ErrorAssertionFunc {
+	return func(t TestingT, err error, i ...interface{}) {
+		if h, ok := t.(tHelper); ok {
+			h.Helper()
+		}
+
+		ErrorAs(t, err, expectedInterface, i...)
+	}
+}
+
 //go:generate sh -c "cd ../_codegen && go build && cd - && ../_codegen/_codegen -output-package=require -template=require.go.tmpl -include-format-funcs"