[Kinetics] Simplify input for extensible interface reactions

Fixes #1620

src/kinetics/Reaction.cpp

@@ -113,7 +113,7 @@ Reaction::Reaction(const AnyMap& node, const Kinetics& kin)
             if (!ba::starts_with(rate_type, "sticking-")) {
                 rateNode["type"] = "sticking-" + rate_type;
             }
-        } else {
+        } else if (rate_type == "Arrhenius") { // no explicitly-specified type
             throw InputFileError("Reaction::Reaction", input,
                 "Unable to infer interface reaction type.");
         }

test/data/extensible-reactions.yaml

@@ -23,6 +23,5 @@ reactions:
 surface-reactions:
 - equation: H(S) + OH(S) <=> H2O(S) + PT(S)
   type: foo-rate
-  rate-constant: {}
   A: 1.3e+14
   E: 71.3

test/python/test_reaction.py

@@ -1722,6 +1722,9 @@ class TestExtensible2(utilities.CanteraTest):
         T = 432.0
         surf.adjacent["gas"].TP = T, ct.one_atm
         assert surf.forward_rate_constants[0] == approx(1.3e14 * np.exp(-71.3 / T))
+        input_data = surf.reaction(0).input_data
+        assert input_data["type"] == "foo-rate"
+        assert "rate-constant" not in input_data
 
 
 @ct.extension(name="user-rate-2", data=UserRate1Data)

test/python/user_ext.py

@@ -47,7 +47,7 @@ class FooRateData(ct.ExtensibleRateData):
         return True
 
 
-@ct.extension(name="interface-foo-rate", data=FooRateData)
+@ct.extension(name="foo-rate", data=FooRateData)
 class FooRate(ct.ExtensibleRate):
     __slots__ = ("A", "E")