fix(core): render list

Fixes #7253

core/src/main/java/io/kestra/core/models/property/Property.java

@@ -22,6 +22,8 @@
 import java.util.Map;
 import java.util.Objects;
 
+import static io.kestra.core.utils.Rethrow.throwFunction;
+
 /**
  * Define a plugin properties that will be rendered and converted to a target type at use time.
  *
@@ -136,12 +138,29 @@ public static <T, I> T asList(Property<T> property, RunContext runContext, Class
      *
      * @see io.kestra.core.runners.RunContextProperty#asList(Class, Map)
      */
+    @SuppressWarnings("unchecked")
     public static <T, I> T asList(Property<T> property, RunContext runContext, Class<I> itemClazz, Map<String, Object> variables) throws IllegalVariableEvaluationException {
         if (property.value == null) {
-            String rendered =  runContext.render(property.expression, variables);
             JavaType type = MAPPER.getTypeFactory().constructCollectionLikeType(List.class, itemClazz);
             try {
-                property.value = MAPPER.readValue(rendered, type);
+                String trimmedExpression = property.expression.trim();
+                // We need to detect if the expression is already a list or if it's a pebble expression (for eg. referencing a variable containing a list).
+                // Doing that allows us to, if it's an expression, first render then read it as a list.
+                if (trimmedExpression.startsWith("{{") && trimmedExpression.endsWith("}}")) {
+                    property.value = MAPPER.readValue(runContext.render(property.expression, variables), type);
+                }
+                // Otherwise if it's already a list, we read it as a list first then render it from run context which handle list rendering by rendering each item of the list
+                else {
+                    List<?> asRawList = MAPPER.readValue(runContext.render(property.expression, variables), List.class);
+                    property.value = (T) asRawList.stream()
+                        .map(throwFunction(item -> {
+                            if (item instanceof String str) {
+                                return MAPPER.convertValue(str, itemClazz);
+                            }
+                            return item;
+                        }))
+                        .toList();
+                }
             } catch (JsonProcessingException e) {
                 throw new IllegalVariableEvaluationException(e);
             }

core/src/test/java/io/kestra/core/models/property/PropertyTest.java

@@ -298,6 +298,30 @@ void arrayAndMapToRender() throws Exception {
         assertThat(output.getMap().get("mapKey2"), is("mapValue2"));
     }
 
+    @Test
+    void aListToRender() throws Exception {
+        var task = DynamicPropertyExampleTask.builder()
+            .items(new Property<>("""
+                ["python test.py --input1 \\"{{ item1 }}\\" --input2 \\"{{ item2 }}\\""]"""))
+            .properties(new Property<>("""
+                {
+                  "key1": "{{value1}}",
+                  "key2": "{{value2}}"
+                }"""))
+            .build();
+        var runContext = runContextFactory.of(Map.ofEntries(
+            entry("item1", "item1"),
+            entry("item2", "item2"),
+            entry("value1", "value1"),
+            entry("value2", "value2")
+        ));
+
+        var output = task.run(runContext);
+
+        assertThat(output, notNullValue());
+        assertThat(output.getList(), containsInAnyOrder("python test.py --input1 \"item1\" --input2 \"item2\""));
+    }
+
     @Builder
     @Getter
     private static class TestObj {