test: verify tree utility functions

tests/tree.test.ts

@@ -0,0 +1,17 @@
+import { expect } from "chai";
+
+import { getAvailableDFTFunctionals, getPseudopotentialTypes } from "../src/tree";
+
+describe("tree", () => {
+    it("can get a list of available DFT functionals", () => {
+        const functionals = getAvailableDFTFunctionals();
+        const supportedFunctionals = ["pbe", "hse06", "b3lyp", "pz"];
+        expect(functionals).to.have.members(supportedFunctionals);
+    });
+
+    it("can get a list of pseudopotential types", () => {
+        const ppTypes = getPseudopotentialTypes();
+        const supportedPseudoTypes = ["paw", "us", "nc", "any"];
+        expect(ppTypes).to.have.members(supportedPseudoTypes);
+    });
+});