improvement: type-safe values for time units

garden-io · May 14, 2024 · ef87fee · ef87fee
1 parent 3aa1661
commit ef87fee
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/core/src/template-string/date-functions.ts b/core/src/template-string/date-functions.ts
@@ -10,6 +10,9 @@ import type { TemplateHelperFunction } from "./functions.js"
 import { joi } from "../config/common.js"
 import { format as formatFns, add } from "date-fns"
 
+const validTimeUnits = ["years", "months", "weeks", "days", "hours", "minutes", "seconds", "milliseconds"] as const
+type TimeUnit = typeof validTimeUnits[number]
+
 export const dateHelperFunctionSpecs: TemplateHelperFunction[] = [
   {
     name: "formatDate",
@@ -38,7 +41,7 @@ export const dateHelperFunctionSpecs: TemplateHelperFunction[] = [
       amount: joi.number().required().description("The amount to modify or set the date by."),
       unit: joi
         .string()
-        .valid("years", "months", "weeks", "days", "hours", "minutes", "seconds", "milliseconds")
+        .valid(...validTimeUnits)
         .required()
         .description("The unit to modify or set."),
       mode: joi.string().valid("add", "set").description("Mode to either add or set the unit.").default("add"),
@@ -49,7 +52,7 @@ export const dateHelperFunctionSpecs: TemplateHelperFunction[] = [
       { input: ["2021-01-01T00:00:00Z", -1, "days", "add"], output: "2020-12-31T00:00:00.000Z" },
       { input: ["2021-01-01T00:00:00Z", 30, "seconds", "set"], output: "2021-01-01T00:00:30.000Z" },
     ],
-    fn: (date: string, amount: number, unit: string, mode: string) => {
+    fn: (date: string, amount: number, unit: TimeUnit, mode: string) => {
       const dateClone = new Date(date)
       switch (mode) {
         case "add":
@@ -78,7 +81,7 @@ export const dateHelperFunctionSpecs: TemplateHelperFunction[] = [
               dateClone.setMilliseconds(amount)
               break
             default:
-              throw new Error("Invalid unit")
+              return unit satisfies never
           }
           return dateClone.toISOString()
         default: