yaml: Fix indentation with dictionary when editing (#40913)

Closes #39570 

Release Notes:

- Fixed indentation with dictionary when editing YAML file.

---------

Signed-off-by: Benjamin <5719034+bnjjj@users.noreply.github.com>

crates/editor/src/editor_tests.rs

@@ -3136,6 +3136,77 @@ fn test_newline(cx: &mut TestAppContext) {
     });
 }
 
+#[gpui::test]
+async fn test_newline_yaml(cx: &mut TestAppContext) {
+    init_test(cx, |_| {});
+
+    let mut cx = EditorTestContext::new(cx).await;
+    let yaml_language = languages::language("yaml", tree_sitter_yaml::LANGUAGE.into());
+    cx.update_buffer(|buffer, cx| buffer.set_language(Some(yaml_language), cx));
+
+    // Object (between 2 fields)
+    cx.set_state(indoc! {"
+    test:ˇ
+    hello: bye"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        ˇ
+    hello: bye"});
+
+    // Object (first and single line)
+    cx.set_state(indoc! {"
+    test:ˇ"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        ˇ"});
+
+    // Array with objects (after first element)
+    cx.set_state(indoc! {"
+    test:
+        - foo: barˇ"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        - foo: bar
+        ˇ"});
+
+    // Array with objects and comment
+    cx.set_state(indoc! {"
+    test:
+        - foo: bar
+        - bar: # testˇ"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        - foo: bar
+        - bar: # test
+            ˇ"});
+
+    // Array with objects (after second element)
+    cx.set_state(indoc! {"
+    test:
+        - foo: bar
+        - bar: fooˇ"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        - foo: bar
+        - bar: foo
+        ˇ"});
+
+    // Array with strings (after first element)
+    cx.set_state(indoc! {"
+    test:
+        - fooˇ"});
+    cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+    cx.assert_editor_state(indoc! {"
+    test:
+        - foo
+        ˇ"});
+}
+
 #[gpui::test]
 fn test_newline_with_old_selections(cx: &mut TestAppContext) {
     init_test(cx, |_| {});

crates/language/src/language.rs

@@ -680,7 +680,7 @@ pub struct CodeLabelBuilder {
     filter_range: Range<usize>,
 }
 
-#[derive(Clone, Deserialize, JsonSchema)]
+#[derive(Clone, Deserialize, JsonSchema, Debug)]
 pub struct LanguageConfig {
     /// Human-readable name of the language.
     pub name: LanguageName,
@@ -823,7 +823,7 @@ pub struct LanguageMatcher {
 }
 
 /// The configuration for JSX tag auto-closing.
-#[derive(Clone, Deserialize, JsonSchema)]
+#[derive(Clone, Deserialize, JsonSchema, Debug)]
 pub struct JsxTagAutoCloseConfig {
     /// The name of the node for a opening tag
     pub open_tag_node_name: String,

crates/languages/src/yaml/config.toml

@@ -12,6 +12,13 @@ brackets = [
 
 auto_indent_on_paste = false
 auto_indent_using_last_non_empty_line = false
-increase_indent_pattern = "^[^#]*:\\s*[|>]?\\s*$"
+# 1st block to match basic elements followed by ':' like 'test: ' for example
+# 2nd block to match for first element in an array if it's an object
+# For example:
+# ```yaml
+# test:
+#   - first: one
+# ```
+increase_indent_pattern = "(:?^[^#]*:\\s*[|>]?\\s*$)|(:?^\\s*-[^#]*:\\s*(:?#+.*)$)"
 prettier_parser_name = "yaml"
 tab_size = 2