[WIP] Add comments above every function definition

web/src/components/form/Form.svelte

@@ -12,6 +12,7 @@
   let interpolatedResult = "";
   let error = "";
 
+  /** Handles form submission by fetching calculation results from the API and updating the displayed output. */
   async function onSubmit(event: Event) {
     event.preventDefault();
 

web/src/pages/api/calc.ts

@@ -2,6 +2,7 @@ import { getResults } from "../../utils/inactivation";
 import { parseQueryParams } from "../../utils/parseQueryParams";
 import { validate } from "../../utils/validate";
 
+/** Handles GET requests to the calc API endpoint by parsing query parameters, validating them, and returning the calculated inactivation results as JSON. */
 export async function get({ params, request }) {
   const queryParams = parseQueryParams(request.url);
   const [validatedParams, error] = validate(queryParams);

web/src/utils/validate.ts

@@ -1,6 +1,7 @@
 const methodologies = ["round", "interpolate", "formula"] as const;
 export type Methodology = (typeof methodologies)[number];
 
+/** Returns true if the given value is a valid methodology string. */
 function isValidMethodology(methodology: any) {
   if (typeof methodology !== "string") return false;
   return methodologies.includes(methodology as Methodology);
@@ -14,6 +15,7 @@ const disinfectants = [
 ] as const;
 export type Disinfectant = (typeof disinfectants)[number];
 
+/** Returns true if the given value is a valid disinfectant string. */
 function isValidDisinfectant(disinfectant: any) {
   if (typeof disinfectant !== "string") return false;
   return disinfectants.includes(disinfectant as Disinfectant);
@@ -22,21 +24,25 @@ function isValidDisinfectant(disinfectant: any) {
 const pathogens = ["giardia", "virus"] as const;
 export type Pathogen = (typeof pathogens)[number];
 
+/** Returns true if the given value is a valid pathogen string. */
 function isValidPathogen(pathogen: any) {
   if (typeof pathogen !== "string") return false;
   return pathogens.includes(pathogen as Pathogen);
 }
 
+/** Returns true if the given value is a valid temperature number (greater than 0 and up to 25°C inclusive). */
 function isValidTemperature(temperature: any) {
   if (typeof temperature !== "number") return false;
   return 0 < temperature && temperature <= 25;
 }
 
+/** Returns true if the given value is a valid pH number (between 6 and 9 inclusive). */
 function isValidPh(ph: any) {
   if (typeof ph !== "number") return false;
   return 6 <= ph && ph <= 9;
 }
 
+/** Returns true if the given value is a valid concentration number (greater than 0 and up to 3 mg/L inclusive). */
 function isValidConcentration(concentration: any) {
   if (typeof concentration !== "number") return false;
   return 0 < concentration && concentration <= 3;
@@ -45,6 +51,7 @@ function isValidConcentration(concentration: any) {
 // TODO should these be strings?
 const inactivationLogs = [2, 3, 4];
 const giardiaInactivationLogs = [0.5, 1, 1.5, 2, 2.5, 3];
+/** Returns true if the given value is a valid inactivation log number for the given pathogen type. */
 function isValidInactivationLog(inactivationLog: any, isGiardia?: boolean) {
   if (typeof inactivationLog !== "number") return false;
   return (isGiardia ? giardiaInactivationLogs : inactivationLogs).includes(