documentation: add code comments to enforceEager

packages/n4s/src/runtime/enforceEager.ts

@@ -8,19 +8,30 @@ import { transformResult } from 'transformResult';
 
 type IRules = n4s.IRules<Record<string, any>>;
 
+// eslint-disable-next-line max-lines-per-function
 export default function enforceEager(value: RuleValue): IRules {
   const target = {} as IRules;
+
+  // This condition is for when we don't have proxy support (ES5).
+  // In this case, we need to manually assign the rules to the target object on runtime.
+  // The follow up proxy block is used in case we do have proxy support, and we can assign each rule upon invocation.
   if (!isProxySupported()) {
+    // We iterate over each of the rules, and add them to the target object being return by enforce
     eachEnforceRule((ruleName: KBaseRules, ruleFn) => {
+      // We then wrap the rule with `genRuleCall` that adds the base enforce behavior
       target[ruleName] = genRuleCall(target, ruleFn, ruleName);
     });
 
     return target;
   }
 
+  // We create a proxy intercepting access to the target object (which is empty).
   const proxy: IRules = new Proxy(target, {
     get: (_, ruleName: string) => {
+      // On property access, we identify if it is a rule or not.
       const rule = getRule(ruleName);
+
+      // If it is a rule, we wrap it with `genRuleCall` that adds the base enforce behavior
       if (rule) {
         return genRuleCall(proxy, rule, ruleName);
       }
@@ -29,12 +40,21 @@ export default function enforceEager(value: RuleValue): IRules {
 
   return proxy;
 
+  // This function is used to wrap a rule with the base enforce behavior
+  // It takes the target object, the rule function, and the rule name
+  // It then returns the rule, in a manner that can be used by enforce
   function genRuleCall(target: IRules, rule: RuleBase, ruleName: string) {
     return function ruleCall(...args: Args) {
+      // Order of operation:
+      // 1. Create a context with the value being enforced
+      // 2. Call the rule within the context, and pass over the arguments passed to it
+      // 3. Transform the result to the correct output format
       const transformedResult = ctx.run({ value }, () =>
         transformResult(rule(value, ...args), ruleName, value, ...args)
       );
 
+      // On rule failure (the result is false), we either throw an error
+      // or throw a string value if the rule has a message defined in it.
       invariant(
         transformedResult.pass,
         isNullish(transformedResult.message)