perf: ⚡️ use LUTs instead of switch-case

apps/api/src/lib/utils.ts

@@ -1,8 +1,27 @@
-import { Course as PrismaCourse, CourseLevel as PrismaCourseLevel } from "@libs/db";
-import { Course, CourseLevel, GE, GECategory, PrerequisiteTree } from "@peterportal-api/types";
+import { Course as PrismaCourse } from "@libs/db";
+import { Course, CourseLevel, GECategory, PrerequisiteTree } from "@peterportal-api/types";
 
 const days = ["Su", "M", "Tu", "W", "Th", "F", "Sa"];
 
+const courseLevels: Record<string, CourseLevel> = {
+  LowerDiv: "Lower Division (1-99)",
+  UpperDiv: "Upper Division (100-199)",
+  Graduate: "Graduate/Professional Only (200+)",
+};
+
+const geMapping: Record<string, GECategory> = {
+  "GE-1A": "GE Ia: Lower Division Writing",
+  "GE-1B": "GE Ib: Upper Division Writing",
+  "GE-2": "GE II: Science and Technology",
+  "GE-3": "GE III: Social & Behavioral Sciences",
+  "GE-4": "GE IV: Arts and Humanities",
+  "GE-5A": "GE Va: Quantitative Literacy",
+  "GE-5B": "GE Vb: Formal Reasoning",
+  "GE-6": "GE VI: Language Other Than English",
+  "GE-7": "GE VII: Multicultural Studies",
+  "GE-8": "GE VIII: International/Global Issues",
+};
+
 /**
  * Input to a transform function.
  */
@@ -40,45 +59,8 @@ export const flattenDayStringsAndSplit = (value: TransformInput): TransformOutpu
     : undefined;
 
 export function normalizeCourse(course: PrismaCourse): Course {
-  let courseLevel: CourseLevel;
-  switch (course.courseLevel as PrismaCourseLevel) {
-    case "LowerDiv":
-      courseLevel = "Lower Division (1-99)";
-      break;
-    case "UpperDiv":
-      courseLevel = "Upper Division (100-199)";
-      break;
-    case "Graduate":
-      courseLevel = "Graduate/Professional Only (200+)";
-      break;
-  }
-  const geList = (course.geList as Array<Omit<GE, "ANY">>).map((x): GECategory => {
-    switch (x) {
-      case "GE-1A":
-        return "GE Ia: Lower Division Writing";
-      case "GE-1B":
-        return "GE Ib: Upper Division Writing";
-      case "GE-2":
-        return "GE II: Science and Technology";
-      case "GE-3":
-        return "GE III: Social & Behavioral Sciences";
-      case "GE-4":
-        return "GE IV: Arts and Humanities";
-      case "GE-5A":
-        return "GE Va: Quantitative Literacy";
-      case "GE-5B":
-        return "GE Vb: Formal Reasoning";
-      case "GE-6":
-        return "GE VI: Language Other Than English";
-      case "GE-7":
-        return "GE VII: Multicultural Studies";
-      case "GE-8":
-        return "GE VIII: International/Global Issues";
-      // this branch should never happen
-      default:
-        throw new Error();
-    }
-  });
+  const courseLevel = courseLevels[course.courseLevel];
+  const geList = (course.geList as string[]).map((x) => geMapping[x]);
   return {
     ...course,
     courseLevel,