Issue #139: Implement DIFF_CHANGED_FILES diff function

Author: AmrDeveloper

crates/gitql-core/src/values/array.rs

@@ -35,11 +35,15 @@ impl ArrayValue {
 impl Value for ArrayValue {
     fn literal(&self) -> String {
         let mut str = String::new();
-        let last_position = self.values.len() - 1;
+        let elements = &self.values;
+        if elements.is_empty() {
+            return "[]".to_string();
+        }
+
         str += "[";
-        for (pos, element) in self.values.iter().enumerate() {
+        for (pos, element) in elements.iter().enumerate() {
             str += &element.literal();
-            if pos != last_position {
+            if pos + 1 != elements.len() {
                 str += ", ";
             }
         }

docs/gitql_functions.md

@@ -11,15 +11,16 @@ those functions are available only in the gitql application.
 
 ### GitQL Diffs functions
 
-| Name                               | Parameters        | Return  | Description                                                              |
-| ---------------------------------- | ----------------- | ------- | ------------------------------------------------------------------------ |
-| DIFF_CONTENT                       | DiffChanges       | Text    | Return the full content of all changes appended together.                |
-| DIFF_ADDED_CONTENT                 | DiffChanges       | Text    | Return the added content of all changes appended together.               |
-| DIFF_DELETED_CONTENT               | DiffChanges       | Text    | Return the deleted content of all changes appended together.             |
-| DIFF_MODIFIED_CONTENT              | DiffChanges       | Text    | Return the modified content of all changes appended together.            |
-| DIFF_CONTENT_CONTAINS              | DiffChanges, Text | Text    | Return true if the all content of changes contains second argument.      |
-| DIFF_ADDED_CONTENT_CONTAINS        | DiffChanges, Text | Text    | Return true if the added content of changes contains second argument.    |
-| DIFF_DELETED_CONTENT_CONTAINS      | DiffChanges, Text | Text    | Return true if the deleted content of changes contains second argument.  |
-| DIFF_MODIFICATION_CONTENT_CONTAINS | DiffChanges, Text | Text    | Return true if the modified content of changes contains second argument. |
-| DIFF_FILES_COUNT                   | DiffChanges       | Integer | Return number of unique files changes in this commit.                    |
-| IS_DIFF_HAS_FILE                   | DiffChanges, Text | Boolean | Return true if this diff changes contains file.                          |
+| Name                               | Parameters        | Return      | Description                                                              |
+| ---------------------------------- | ----------------- | ----------- | ------------------------------------------------------------------------ |
+| DIFF_CONTENT                       | DiffChanges       | Text        | Return the full content of all changes appended together.                |
+| DIFF_ADDED_CONTENT                 | DiffChanges       | Text        | Return the added content of all changes appended together.               |
+| DIFF_DELETED_CONTENT               | DiffChanges       | Text        | Return the deleted content of all changes appended together.             |
+| DIFF_MODIFIED_CONTENT              | DiffChanges       | Text        | Return the modified content of all changes appended together.            |
+| DIFF_CONTENT_CONTAINS              | DiffChanges, Text | Text        | Return true if the all content of changes contains second argument.      |
+| DIFF_ADDED_CONTENT_CONTAINS        | DiffChanges, Text | Text        | Return true if the added content of changes contains second argument.    |
+| DIFF_DELETED_CONTENT_CONTAINS      | DiffChanges, Text | Text        | Return true if the deleted content of changes contains second argument.  |
+| DIFF_MODIFICATION_CONTENT_CONTAINS | DiffChanges, Text | Text        | Return true if the modified content of changes contains second argument. |
+| DIFF_CHANGED_FILES                 | DiffChanges       | Array<Text> | Return changes files in this change as array of strings.                 |
+| DIFF_FILES_COUNT                   | DiffChanges       | Integer     | Return number of unique files changes in this commit.                    |
+| IS_DIFF_HAS_FILE                   | DiffChanges, Text | Boolean     | Return true if this diff changes contains file.                          |

src/gitql/functions/diffs.rs

@@ -1,11 +1,13 @@
 use std::collections::HashMap;
 use std::collections::HashSet;
 
+use gitql_ast::types::array::ArrayType;
 use gitql_ast::types::boolean::BoolType;
 use gitql_ast::types::integer::IntType;
 use gitql_ast::types::text::TextType;
 use gitql_core::signature::Signature;
 use gitql_core::signature::StandardFunction;
+use gitql_core::values::array::ArrayValue;
 use gitql_core::values::base::Value;
 use gitql_core::values::boolean::BoolValue;
 use gitql_core::values::integer::IntValue;
@@ -36,6 +38,7 @@ pub(crate) fn register_diffs_functions(map: &mut HashMap<&'static str, StandardF
         diff_changes_modified_content_contains,
     );
 
+    map.insert("diff_changed_files", diff_changed_files);
     map.insert("diff_files_count", diff_changes_files_count);
 
     map.insert("is_diff_has_file", diff_changes_contains_file);
@@ -91,6 +94,12 @@ pub(crate) fn register_diffs_function_signatures(map: &mut HashMap<&'static str,
             .add_parameter(Box::new(TextType)),
     );
 
+    map.insert(
+        "diff_changed_files",
+        Signature::with_return(Box::new(ArrayType::new(Box::new(TextType))))
+            .add_parameter(Box::new(DiffChangesType)),
+    );
+
     map.insert(
         "diff_files_count",
         Signature::with_return(Box::new(IntType)).add_parameter(Box::new(DiffChangesType)),
@@ -217,6 +226,17 @@ fn diff_changes_modified_content_contains(values: &[Box<dyn Value>]) -> Box<dyn
     Box::new(BoolValue::new_false())
 }
 
+fn diff_changed_files(values: &[Box<dyn Value>]) -> Box<dyn Value> {
+    if let Some(changes) = values[0].as_any().downcast_ref::<DiffChangesValue>() {
+        let mut elements: Vec<Box<dyn Value>> = vec![];
+        for change in changes.changes.iter() {
+            elements.push(Box::new(TextValue::new(change.location.to_string())));
+        }
+        return Box::new(ArrayValue::new(elements, Box::new(TextType)));
+    }
+    Box::new(ArrayValue::empty(Box::new(TextType)))
+}
+
 fn diff_changes_files_count(values: &[Box<dyn Value>]) -> Box<dyn Value> {
     if let Some(changes) = values[0].as_any().downcast_ref::<DiffChangesValue>() {
         let mut unique_files: HashSet<&String> = HashSet::new();