chore: clarify optional field errors

Copilot · rotu · web-flow · commit 086b2b882f59 · 2026-04-02T22:37:05.000Z
Agent-Logs-Url: https://github.com/rotu/structview/sessions/0716fb80-af23-468f-86bd-27d35fdca170 Co-authored-by: rotu <119948+rotu@users.noreply.github.com>
diff --git a/fields.ts b/fields.ts
@@ -75,7 +75,9 @@ function resolveBooleanFieldValue(
 ): boolean {
   const result = resolveFieldValue(struct, value)
   if (typeof result !== "boolean") {
-    throw new TypeError("present must resolve to a boolean")
+    throw new TypeError(
+      "optional field presence condition must resolve to a boolean",
+    )
   }
   return result
 }
@@ -421,7 +423,7 @@ export function optional<T>(
   const getter = field.get
   if (typeof getter !== "function") {
     throw new TypeError(
-      "optional() requires a field descriptor with a getter function",
+      "optional() requires a field descriptor with a defined 'get' method",
     )
   }
   const presenceConfig = typeof present === "object"

Original file line number	Diff line number	Diff line change
`@@ -75,7 +75,9 @@ function resolveBooleanFieldValue(`
`75`	`75`	`): boolean {`
`76`	`76`	`const result = resolveFieldValue(struct, value)`
`77`	`77`	`if (typeof result !== "boolean") {`
`78`		`- throw new TypeError("present must resolve to a boolean")`
	`78`	`+ throw new TypeError(`
	`79`	`+ "optional field presence condition must resolve to a boolean",`
	`80`	`+ )`
`79`	`81`	`}`
`80`	`82`	`return result`
`81`	`83`	`}`
`@@ -421,7 +423,7 @@ export function optional<T>(`
`421`	`423`	`const getter = field.get`
`422`	`424`	`if (typeof getter !== "function") {`
`423`	`425`	`throw new TypeError(`
`424`		`- "optional() requires a field descriptor with a getter function",`
	`426`	`+ "optional() requires a field descriptor with a defined 'get' method",`
`425`	`427`	`)`
`426`	`428`	`}`
`427`	`429`	`const presenceConfig = typeof present === "object"`