Generically handle all method visibility modifiers (#369)

* Fixtures

* Properly handle end spacing for all method-modifiers

* Make index a constant and add some more explanatory comments

Co-authored-by: Reese Williams <[email protected]>

fixtures/small/visibility_modifier_actual.rb

@@ -0,0 +1,23 @@
+class Foo
+  private def bar
+    42
+  end
+
+  private def baz(a, b, c)
+    a + b + c
+  end
+end
+
+module WhiteTeaBowl
+  sig do
+    params(walking_this: Path)
+  end
+  module_function def i_choose_one; end
+
+  sig do
+    void
+  end
+  patch_of def sunlight
+    "after another"
+  end
+end

fixtures/small/visibility_modifier_expected.rb

@@ -0,0 +1,24 @@
+class Foo
+  private def bar
+    42
+  end
+
+  private def baz(a, b, c)
+    a + b + c
+  end
+end
+
+module WhiteTeaBowl
+  sig do
+    params(walking_this: Path)
+  end
+  module_function def i_choose_one
+  end
+
+  sig do
+    void
+  end
+  patch_of def sunlight
+    "after another"
+  end
+end

librubyfmt/src/intermediary.rs

@@ -222,6 +222,13 @@ impl Intermediary {
         }
     }
 
+    pub fn insert_blankline_from_end(&mut self, index_from_end: usize) {
+        self.tokens.insert(
+            self.tokens.len() - index_from_end,
+            ConcreteLineToken::HardNewLine,
+        )
+    }
+
     pub fn insert_trailing_blankline(&mut self, _bl: BlanklineReason) {
         if self.index_of_last_hard_newline <= 2 {
             self.tokens.insert(

librubyfmt/src/line_tokens.rs

@@ -116,19 +116,6 @@ impl ConcreteLineToken {
         }
     }
 
-    pub fn is_method_visibility_modifier(&self) -> bool {
-        match self {
-            Self::DirectPart { part } => {
-                part == "public"
-                    || part == "private"
-                    || part == "protected"
-                    || part == "public_class_method"
-                    || part == "private_class_method"
-            }
-            _ => false,
-        }
-    }
-
     pub fn is_single_line_breakable_garbage(&self) -> bool {
         match self {
             Self::DirectPart { part } => part == &"".to_string(),

librubyfmt/src/render_queue_writer.rs

@@ -63,16 +63,29 @@ impl RenderQueueWriter {
             }
 
             if let Some(
-                [&ConcreteLineToken::End, &ConcreteLineToken::AfterCallChain, &ConcreteLineToken::HardNewLine, &ConcreteLineToken::Indent { .. }, x],
-            ) = accum.last::<5>()
+                [&ConcreteLineToken::End, &ConcreteLineToken::AfterCallChain, &ConcreteLineToken::HardNewLine, &ConcreteLineToken::Indent { .. }, x, maybe_space, maybe_def],
+            ) = accum.last::<7>()
             {
                 match x {
                     ConcreteLineToken::DefKeyword => {}
                     _ => {
                         if x.is_in_need_of_a_trailing_blankline()
-                            && !x.is_method_visibility_modifier()
+                            && !matches!(
+                                (maybe_space, maybe_def),
+                                (ConcreteLineToken::Space, ConcreteLineToken::DefKeyword)
+                            )
                         {
-                            accum.insert_trailing_blankline(BlanklineReason::ComesAfterEnd);
+                            // If we're here, the last few tokens must look like this:
+                            // | token             | index_from_end |
+                            // |  End              | 6              |
+                            // |. AfterCallChain   | 5              |
+                            // |  HardNewline      | 4              | <-- insert after this token
+                            // |. Indent           | 3 .            |
+                            // |  (ArbitraryToken) | 2              |
+                            // |  (ArbitraryToken) | 1              |
+                            // |  (ArbitraryToken) | 0              |
+                            const LAST_NEWLINE_INDEX_FROM_END: usize = 4;
+                            accum.insert_blankline_from_end(LAST_NEWLINE_INDEX_FROM_END);
                         }
                     }
                 }