Placing comments in the middle of a member access chained expression in the correct place

Author: Janther

src/slang-comments/handlers/handle-member-access-expression-comments.ts

@@ -0,0 +1,39 @@
+import { NonterminalKind } from '@nomicfoundation/slang/cst';
+import { util } from 'prettier';
+
+import type { HandlerParams } from './types.d.ts';
+
+const { addLeadingComment, addTrailingComment } = util;
+
+export default function handleMemberAccessExpressionComments({
+  precedingNode,
+  enclosingNode,
+  followingNode,
+  comment
+}: HandlerParams): boolean {
+  if (enclosingNode?.kind !== NonterminalKind.MemberAccessExpression) {
+    return false;
+  }
+
+  if (followingNode !== undefined && followingNode === enclosingNode.operand) {
+    addLeadingComment(followingNode, comment);
+    return true;
+  }
+
+  if (
+    precedingNode !== undefined &&
+    followingNode !== undefined &&
+    precedingNode === enclosingNode.operand &&
+    followingNode === enclosingNode.member
+  ) {
+    addTrailingComment(precedingNode, comment);
+    return true;
+  }
+
+  if (precedingNode !== undefined && precedingNode === enclosingNode.member) {
+    addTrailingComment(precedingNode, comment);
+    return true;
+  }
+
+  return false;
+}

src/slang-comments/handlers/index.ts

@@ -5,6 +5,7 @@ import handleElseBranchComments from './handle-else-branch-comments.js';
 import handleIfStatementComments from './handle-if-statement-comments.js';
 import handleInterfaceDefinitionComments from './handle-interface-definition-comments.js';
 import handleLibraryDefinitionComments from './handle-library-definition-comments.js';
+import handleMemberAccessExpressionComments from './handle-member-access-expression-comments.js';
 import handleModifierInvocationComments from './handle-modifier-invocation-comments.js';
 import handleParametersDeclarationComments from './handle-parameters-declaration-comments.js';
 import handlePositionalArgumentsDeclarationComments from './handle-positional-arguments-declaration-comments.js';
@@ -22,6 +23,7 @@ export default [
   handleIfStatementComments,
   handleInterfaceDefinitionComments,
   handleLibraryDefinitionComments,
+  handleMemberAccessExpressionComments,
   handleModifierInvocationComments,
   handleParametersDeclarationComments,
   handlePositionalArgumentsDeclarationComments,

src/slang-nodes/MemberAccessExpression.ts

@@ -128,8 +128,13 @@ export class MemberAccessExpression extends SlangNode {
   }
 
   print(path: AstPath<MemberAccessExpression>, print: PrintFunction): Doc {
+    let operandDoc = path.call(print, 'operand');
+    if (Array.isArray(operandDoc)) {
+      operandDoc = operandDoc.flat();
+    }
+
     const document = [
-      path.call(print, 'operand'),
+      operandDoc,
       label('separator', [softline, '.']),
       path.call(print, 'member')
     ].flat();

tests/format/MemberAccess/MemberAccess.sol

@@ -62,6 +62,19 @@ contract MemberAccess {
             abi.encodeWithSelector(f.selector),
             abi.encode(returned1)
         );
+// Comments in between the chain
+        game.
+// CONFIG
+// Do not touch
+config. // Window
+// Resolution 1000
+resolveWindow = 1000;
+config.defaultDelay = 0;
+begin
+    .// Comment 1
+    functionCall(/* Comment about parameter */ parameter)
+    .// Comment 2
+    end;
     }
 }
 

tests/format/MemberAccess/__snapshots__/format.test.js.snap

@@ -70,6 +70,19 @@ contract MemberAccess {
             abi.encodeWithSelector(f.selector),
             abi.encode(returned1)
         );
+// Comments in between the chain
+        game.
+// CONFIG
+// Do not touch
+config. // Window
+// Resolution 1000
+resolveWindow = 1000;
+config.defaultDelay = 0;
+begin
+    .// Comment 1
+    functionCall(/* Comment about parameter */ parameter)
+    .// Comment 2
+    end;
     }
 }
 
@@ -206,6 +219,17 @@ contract MemberAccess {
             abi.encodeWithSelector(f.selector),
             abi.encode(returned1)
         );
+        // Comments in between the chain
+        game
+        // CONFIG
+        // Do not touch
+            .config // Window
+            // Resolution 1000
+            .resolveWindow = 1000;
+        config.defaultDelay = 0;
+        begin // Comment 1
+            .functionCall(/* Comment about parameter */ parameter) // Comment 2
+            .end;
     }
 }