Got add records functioning.

src/lib.rs

@@ -17,6 +17,7 @@ use std::{
 
 struct Request;
 
+#[derive(Clone)]
 enum Field {
     Static(String),
 }
@@ -136,17 +137,52 @@ mod records {
 
 struct Response {
     data: HashMap<String, Vec<Field>>,
+    counter: usize,
 }
 
 impl Response {
     fn new() -> Self {
         Self {
             data: HashMap::new(),
+            counter: 0,
         }
     }
 
-    fn count(&self) -> usize {
-        0
+    fn add(&mut self, rec: Record) -> Result<(), String> {
+        if self.data.is_empty() {
+            for (key, value) in rec.iter() {
+                let mut store = Vec::new();
+                store.push(value.clone());
+                self.data.insert(key.to_string(), store);
+            }
+        } else {
+            for (key, value) in rec.iter() {
+                match self.data.get_mut(key) {
+                    Some(data) => data.push(value.clone()),
+                    None => return Err("bad".to_string()),
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+impl Iterator for Response {
+    type Item = Record;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.data.is_empty() {
+            return None;
+        }
+        let mut rec = Record::new();
+        for (key, value) in self.data.iter() {
+            if self.counter >= value.len() {
+                return None;
+            }
+            rec.add(key, value[self.counter].clone());
+        }
+        self.counter += 1;
+        Some(rec)
     }
 }
 
@@ -156,9 +192,57 @@ mod responses {
 
     #[test]
     fn create_response() {
-        let res = Response::new();
+        let mut res = Response::new();
         assert!(res.data.is_empty());
-        assert_eq!(res.count(), 0);
+        assert!(res.next().is_none());
+    }
+
+    #[test]
+    fn add_records() {
+        let mut res = Response::new();
+        let columns = ["col1", "col2"];
+        let count = 3;
+        let field_cnt = &count * columns.len();
+        let mut fields = 0..field_cnt;
+        for _ in 0..count {
+            let mut rec = Record::new();
+            for col in columns {
+                rec.add(col, fields.next().unwrap().to_string());
+            }
+            res.add(rec);
+        }
+        fields = 0..field_cnt;
+        for _ in 0..count {
+            match res.next() {
+                Some(rec) => {
+                    assert_eq!(rec.len(), columns.len());
+                    for col in columns {
+                        match rec.get(col).unwrap() {
+                            Field::Static(txt) => {
+                                assert_eq!(txt.clone(), fields.next().unwrap().to_string())
+                            }
+                        }
+                    }
+                }
+                None => unreachable!("Should have returned data"),
+            }
+        }
+        assert!(res.next().is_none(), "exceeded the correct of records");
+    }
+
+    #[test]
+    fn number_of_columns_mismatch() {
+        let mut res = Response::new();
+        let mut rec1 = Record::new();
+        let mut rec2 = Record::new();
+        rec1.add("one", "one");
+        rec2.add("one", "one");
+        rec2.add("two", "two");
+        res.add(rec1).unwrap();
+        match res.add(rec2) {
+            Ok(_) => unreachable!("Should not accept additional value"),
+            Err(_) => {}
+        }
     }
 }