Test some validator_info error paths (#20635)

* Test some validator_info error paths

* Fix a linting issue

* Improve test robustness by removing magic numbers

cli/src/validator_info.rs

@@ -412,6 +412,23 @@ mod tests {
     use bincode::{serialize, serialized_size};
     use serde_json::json;
 
+    #[test]
+    fn test_check_details_length() {
+        let short_details = (0..MAX_LONG_FIELD_LENGTH).map(|_| "X").collect::<String>();
+        assert_eq!(check_details_length(short_details), Ok(()));
+
+        let long_details = (0..MAX_LONG_FIELD_LENGTH + 1)
+            .map(|_| "X")
+            .collect::<String>();
+        assert_eq!(
+            check_details_length(long_details),
+            Err(format!(
+                "validator details longer than {:?}-byte limit",
+                MAX_LONG_FIELD_LENGTH
+            ))
+        );
+    }
+
     #[test]
     fn test_check_url() {
         let url = "http://test.com";
@@ -430,6 +447,17 @@ mod tests {
         assert!(is_short_field(long_name.to_string()).is_err());
     }
 
+    #[test]
+    fn test_verify_keybase_username_not_string() {
+        let pubkey = solana_sdk::pubkey::new_rand();
+        let value = Value::Bool(true);
+
+        assert_eq!(
+            verify_keybase(&pubkey, &value).unwrap_err().to_string(),
+            "keybase_username could not be parsed as String: true".to_string()
+        )
+    }
+
     #[test]
     fn test_parse_args() {
         let matches = get_clap_app("test", "desc", "version").get_matches_from(vec![
@@ -507,6 +535,41 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_parse_validator_info_not_validator_info_account() {
+        assert!(parse_validator_info(
+            &Pubkey::default(),
+            &Account {
+                owner: solana_sdk::pubkey::new_rand(),
+                ..Account::default()
+            }
+        )
+        .unwrap_err()
+        .to_string()
+        .contains("is not a validator info account"));
+    }
+
+    #[test]
+    fn test_parse_validator_info_empty_key_list() {
+        let config = ConfigKeys { keys: vec![] };
+        let validator_info = ValidatorInfo {
+            info: String::new(),
+        };
+        let data = serialize(&(config, validator_info)).unwrap();
+
+        assert!(parse_validator_info(
+            &Pubkey::default(),
+            &Account {
+                owner: solana_config_program::id(),
+                data,
+                ..Account::default()
+            },
+        )
+        .unwrap_err()
+        .to_string()
+        .contains("could not be parsed as a validator info account"));
+    }
+
     #[test]
     fn test_validator_info_max_space() {
         // 70-character string