refactor(ext/cron): align error messages (#25300)

Aligns the error messages in the cron extension to be in-line with the
Deno style guide.

https://github.com/denoland/deno/issues/25269

ext/cron/01_cron.ts

@@ -41,7 +41,9 @@ export function formatToCronSchedule(
       } else if (end === undefined && every !== undefined) {
         return "*/" + every;
       } else {
-        throw new TypeError("Invalid cron schedule");
+        throw new TypeError(
+          `Invalid cron schedule: start=${start}, end=${end}, every=${every}`,
+        );
       }
     } else {
       if (typeof exact === "number") {
@@ -103,10 +105,14 @@ function cron(
   handler2?: () => Promise<void> | void,
 ) {
   if (name === undefined) {
-    throw new TypeError("Deno.cron requires a unique name");
+    throw new TypeError(
+      "Cannot create cron job, a unique name is required: received 'undefined'",
+    );
   }
   if (schedule === undefined) {
-    throw new TypeError("Deno.cron requires a valid schedule");
+    throw new TypeError(
+      "Cannot create cron job, a schedule is required: received 'undefined'",
+    );
   }
 
   schedule = parseScheduleToString(schedule);
@@ -119,13 +125,15 @@ function cron(
   if (typeof handlerOrOptions1 === "function") {
     handler = handlerOrOptions1;
     if (handler2 !== undefined) {
-      throw new TypeError("Deno.cron requires a single handler");
+      throw new TypeError(
+        "Cannot create cron job, a single handler is required: two handlers were specified",
+      );
     }
   } else if (typeof handler2 === "function") {
     handler = handler2;
     options = handlerOrOptions1;
   } else {
-    throw new TypeError("Deno.cron requires a handler");
+    throw new TypeError("Cannot create cron job: a handler is required");
   }
 
   const rid = op_cron_create(

ext/cron/lib.rs

@@ -116,12 +116,15 @@ where
 
 fn validate_cron_name(name: &str) -> Result<(), AnyError> {
   if name.len() > 64 {
-    return Err(type_error("Cron name is too long"));
+    return Err(type_error(format!(
+      "Cron name cannot exceed 64 characters: current length {}",
+      name.len()
+    )));
   }
   if !name.chars().all(|c| {
     c.is_ascii_whitespace() || c.is_ascii_alphanumeric() || c == '_' || c == '-'
   }) {
-    return Err(type_error("Invalid cron name. Only alphanumeric characters, whitespace, hyphens, and underscores are allowed"));
+    return Err(type_error("Invalid cron name: only alphanumeric characters, whitespace, hyphens, and underscores are allowed"));
   }
   Ok(())
 }

tests/unit/cron_test.ts

@@ -15,7 +15,7 @@ Deno.test(function noNameTest() {
     // @ts-ignore test
     () => Deno.cron(),
     TypeError,
-    "Deno.cron requires a unique name",
+    "Cannot create cron job, a unique name is required: received 'undefined'",
   );
 });
 
@@ -24,7 +24,7 @@ Deno.test(function noSchedule() {
     // @ts-ignore test
     () => Deno.cron("foo"),
     TypeError,
-    "Deno.cron requires a valid schedule",
+    "Cannot create cron job, a schedule is required: received 'undefined'",
   );
 });
 
@@ -33,7 +33,7 @@ Deno.test(function noHandler() {
     // @ts-ignore test
     () => Deno.cron("foo", "*/1 * * * *"),
     TypeError,
-    "Deno.cron requires a handler",
+    "Cannot create cron job: a handler is required",
   );
 });
 
@@ -66,7 +66,7 @@ Deno.test(function invalidNameTest() {
         () => {},
       ),
     TypeError,
-    "Cron name is too long",
+    "Cron name cannot exceed 64 characters: current length 70",
   );
 });
 
@@ -388,7 +388,7 @@ Deno.test("error on two handlers", () => {
       Deno.cron("abc", "* * * * *", () => {}, () => {});
     },
     TypeError,
-    "Deno.cron requires a single handler",
+    "Cannot create cron job, a single handler is required: two handlers were specified",
   );
 });