From 4fb636186049a6ece09997da6306888156209cbb Mon Sep 17 00:00:00 2001
From: glendc <glen.decauwsemaecker@otainsight.com>
Date: Mon, 8 Apr 2024 13:37:35 +0200
Subject: [PATCH] support append/from_iter with Into

more flexibility without a cost if not desired
---
 venndb-macros/src/generate_db.rs | 18 ++++++++-
 venndb-usage/src/main.rs         | 69 ++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/venndb-macros/src/generate_db.rs b/venndb-macros/src/generate_db.rs
index 424bdb8..77e23aa 100644
--- a/venndb-macros/src/generate_db.rs
+++ b/venndb-macros/src/generate_db.rs
@@ -250,6 +250,11 @@ fn generate_db_struct_method_from_rows(
         name
     );
 
+    let method_iter_doc = format!(
+        "Construct a new database from the given iterator of items that can be turned into [`{}`] instances.",
+        name
+    );
+
     let return_type =
         db_error.generate_fn_output(name_db, quote! { ::std::vec::Vec<#name> }, quote! { Self });
     let append_internal_call = db_error.generate_fn_error_kind_usage(
@@ -273,6 +278,16 @@ fn generate_db_struct_method_from_rows(
             db.rows = rows;
             #fn_result
         }
+
+        #[doc=#method_iter_doc]
+        #vis fn from_iter<I, Item>(iter: I) -> #return_type
+            where
+                I: ::std::iter::IntoIterator<Item = Item>,
+                Item: ::std::convert::Into<#name>,
+        {
+            let rows: ::std::vec::Vec<#name> = iter.into_iter().map(::std::convert::Into::into).collect();
+            Self::from_rows(rows)
+        }
     }
 }
 
@@ -367,8 +382,9 @@ fn generate_db_struct_method_append(
 
     quote! {
         #[doc=#method_doc]
-        #vis fn append(&mut self, data: #name) -> #append_return_type {
+        #vis fn append(&mut self, data: impl ::std::convert::Into<#name>) -> #append_return_type {
             let index = self.rows.len();
+            let data = data.into();
             #append_internal_call
             self.rows.push(data);
             #append_return_output
diff --git a/venndb-usage/src/main.rs b/venndb-usage/src/main.rs
index 4617106..5a05c1f 100644
--- a/venndb-usage/src/main.rs
+++ b/venndb-usage/src/main.rs
@@ -15,6 +15,25 @@ pub struct Employee {
     department: Department,
 }
 
+#[derive(Debug)]
+pub struct L1Engineer {
+    id: u32,
+    name: String,
+}
+
+impl From<L1Engineer> for Employee {
+    fn from(engineer: L1Engineer) -> Employee {
+        Employee {
+            id: engineer.id,
+            name: engineer.name,
+            is_manager: false,
+            is_admin: false,
+            is_active: true,
+            department: Department::Engineering,
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 pub enum Department {
     Engineering,
@@ -77,6 +96,25 @@ mod tests {
         assert_eq!(employee.name, "Alice");
     }
 
+    #[test]
+    fn test_append_into() {
+        let mut db = EmployeeDB::default();
+        db.append(L1Engineer {
+            id: 1,
+            name: "Alice".to_string(),
+        })
+        .unwrap();
+        assert_eq!(db.len(), 1);
+
+        let employee: &Employee = db.get_by_id(&1).unwrap();
+        assert_eq!(employee.id, 1);
+        assert_eq!(employee.name, "Alice");
+        assert!(!employee.is_manager);
+        assert!(!employee.is_admin);
+        assert!(employee.is_active);
+        assert_eq!(employee.department, Department::Engineering);
+    }
+
     #[test]
     fn test_employee_query_filters() {
         let mut db = EmployeeDB::default();
@@ -240,6 +278,37 @@ mod tests {
         assert_eq!(rows[1].id, 2);
     }
 
+    #[test]
+    fn test_from_iter() {
+        let db = EmployeeDB::from_iter([
+            L1Engineer {
+                id: 1,
+                name: "Alice".to_string(),
+            },
+            L1Engineer {
+                id: 2,
+                name: "Bob".to_string(),
+            },
+        ])
+        .unwrap();
+
+        assert_eq!(db.len(), 2);
+        assert_eq!(db.capacity(), 2);
+
+        let mut query = db.query();
+        query.is_manager(true);
+        assert!(query.execute().is_none());
+
+        query
+            .reset()
+            .is_manager(false)
+            .department(Department::Engineering);
+        let results: Vec<_> = query.execute().unwrap().iter().collect();
+        assert_eq!(results.len(), 2);
+        assert_eq!(results[0].id, 1);
+        assert_eq!(results[1].id, 2);
+    }
+
     #[test]
     fn test_query_reset() {
         let mut db = EmployeeDB::default();