Added support for sequence concatination with + (#491)

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to MiniJinja are documented here.
 ## 1.0.20
 
 - Added support for implicit string concatenation for Jinja2 compatibility.  #489
+- Added support for sequence concatenation with the plus operator for Jinja2 compatibility.  #491
 
 ## 1.0.19
 

minijinja/src/value/ops.rs

@@ -181,6 +181,11 @@ macro_rules! math_binop {
 }
 
 pub fn add(lhs: &Value, rhs: &Value) -> Result<Value, Error> {
+    if lhs.kind() == ValueKind::Seq && rhs.kind() == ValueKind::Seq {
+        return Ok(Value::from_iter(
+            lhs.try_iter_owned()?.chain(rhs.try_iter_owned()?),
+        ));
+    }
     match coerce(lhs, rhs) {
         Some(CoerceResult::I128(a, b)) => a
             .checked_add(b)

minijinja/tests/inputs/adding.txt

@@ -6,11 +6,14 @@ Strings:
 {{ 'to' + name + 'you' }}!
 {{ 'to' + 'you' }}!
 
+Sequences:
+{{ [1] + [2] }}
+
 Adding:
 {{ 1 + 2 }}
 
 Minus:
-{{ 2 + 1 }}
+{{ 2 - 1 }}
 
 Divide:
 {{ 100 / 2 }}

minijinja/tests/snapshots/test_templates__vm@adding.txt.snap

@@ -1,6 +1,6 @@
 ---
 source: minijinja/tests/test_templates.rs
-description: "Strings:\n{{ 'to' + name + 'you' }}!\n{{ 'to' + 'you' }}!\n\nAdding:\n{{ 1 + 2 }}\n\nMinus:\n{{ 2 + 1 }}\n\nDivide:\n{{ 100 / 2 }}"
+description: "Strings:\n{{ 'to' + name + 'you' }}!\n{{ 'to' + 'you' }}!\n\nSequences:\n{{ [1] + [2] }}\n\nAdding:\n{{ 1 + 2 }}\n\nMinus:\n{{ 2 - 1 }}\n\nDivide:\n{{ 100 / 2 }}"
 info:
   name: World
 input_file: minijinja/tests/inputs/adding.txt
@@ -9,12 +9,14 @@ Strings:
 toWorldyou!
 toyou!
 
+Sequences:
+[1, 2]
+
 Adding:
 3
 
 Minus:
-3
+1
 
 Divide:
 50.0
-