Infer types for new date functions (#25694)

frontend/src/metabase/lib/expressions/config.js

@@ -363,12 +363,12 @@ export const MBQL_CLAUSES = {
   },
   "date-add": {
     displayName: `dateAdd`,
-    type: "number",
+    type: "expression",
     args: ["expression", "number", "string"],
   },
   "date-subtract": {
     displayName: `dateSubtract`,
-    type: "number",
+    type: "expression",
     args: ["expression", "number", "string"],
   },
 };

frontend/src/metabase/lib/expressions/typeinferencer.js

@@ -12,6 +12,7 @@ export function infer(mbql, env) {
   if (!Array.isArray(mbql)) {
     return typeof mbql;
   }
+
   const op = mbql[0];
   switch (op) {
     case OP.Plus:
@@ -32,16 +33,13 @@ export function infer(mbql, env) {
       return MONOTYPE.Boolean;
   }
 
-  if (op === "case") {
-    const clauses = mbql[1];
-    const first = clauses[0];
-    // TODO: type-checker must ensure the consistent types of all clauses.
-    return infer(first[1], env);
-  }
-
-  if (op === "coalesce") {
-    // TODO: type-checker must ensure the consistent types of all arguments
-    return infer(mbql[1], env);
+  switch (op) {
+    case "case":
+      return infer(mbql[1][0][1], env);
+    case "coalesce":
+    case "date-add":
+    case "date-subtract":
+      return infer(mbql[1], env);
   }
 
   const func = MBQL_CLAUSES[op];