Fix formula functions declared with caps

Author: jstrieb

TODO.md

@@ -162,4 +162,3 @@
     vertical scrolling
   - Accidentally typing "RC" while typing another formula can cause everything
     to hang
-  - Formula functions declared with any caps will not be accessible

src/formula-functions.svelte.js

@@ -42,6 +42,10 @@ export function evalCode(code, ret = () => {}) {
         // Allows user code to show up in the devtools debugger as "user-code.js"
         "\n//# sourceURL=user-code.js",
     );
+    // Canonicalize function names, since only lowercased version is used
+    Object.entries(functions).forEach(([name, f]) => {
+      functions[name.toLocaleLowerCase()] = f;
+    });
     return ret();
   } catch (e) {
     return ret(e);

test/sheet-and-formula.test.js

@@ -668,3 +668,14 @@ test("Negation as a unary operation", async () => {
     [Math.pow(3, -2), Math.pow(3, -2), -2, 3 + 4 + 5],
   ]);
 });
+
+test("Custom formula functions with caps in declaration", async () => {
+  evalCode(
+    `functions.FACTORIAL = (n) => n == 0 ? 1 : (n * functions.FACTORIAL(n - 1))`,
+  );
+  const state = createSheet([["6", "=factorial(RC0)"]]);
+  await expectSheet(state.currentSheet, [[6, 720]]);
+  evalCode(`functions.With_underscores = (n) => n * 2`);
+  state.currentSheet.cells[0][1].formula = "=with_underscores(RC0)";
+  await expectSheet(state.currentSheet, [[6, 12]]);
+});