fix: eliminate repeated printer function execution from our naively-implemented 'call' helper

Author: jtkiesel

packages/prettier-plugin-java/src/printers/blocks-and-statements.ts

@@ -84,10 +84,11 @@ export default {
   ifStatement(path, print) {
     const { children } = path.node;
     const hasEmptyStatement = isEmptyStatement(children.statement[0]);
+    const statements = map(path, print, "statement");
     const statement: Doc[] = [
       "if ",
       indentInParentheses(call(path, print, "expression")),
-      hasEmptyStatement ? ";" : [" ", call(path, print, "statement", 0)]
+      hasEmptyStatement ? ";" : [" ", statements[0]]
     ];
     if (children.Else) {
       const danglingComments = printDanglingComments(path);
@@ -103,7 +104,7 @@ export default {
       const elseHasEmptyStatement = isEmptyStatement(children.statement[1]);
       statement.push(
         "else",
-        elseHasEmptyStatement ? ";" : [" ", call(path, print, "statement", 1)]
+        elseHasEmptyStatement ? ";" : [" ", statements[1]]
       );
     }
     return statement;

packages/prettier-plugin-java/src/printers/expressions.ts

@@ -115,13 +115,14 @@ export default {
 
   conditionalExpression(path, print) {
     const binaryExpression = call(path, print, "binaryExpression");
+    const expressions = map(path, print, "expression");
     return path.node.children.QuestionMark
       ? group(
           indent(
             join(line, [
               binaryExpression,
-              ["? ", call(path, print, "expression", 0)],
-              [": ", call(path, print, "expression", 1)]
+              ["? ", expressions[0]],
+              [": ", expressions[1]]
             ])
           )
         )
@@ -468,9 +469,9 @@ export default {
       return allArgsExpandable;
     }
     const headArgs = args.slice(0, -1);
-    const huggedLastArg = call(
-      path,
+    const huggedLastArg = path.call(
       argPath => print(argPath, { hug: true }),
+      "children",
       "expression",
       args.length - 1
     );
@@ -756,7 +757,6 @@ function printTemplate<
   T extends StringTemplateCstNode | TextBlockTemplateCstNode,
   C extends Exclude<IterProperties<T["children"]>, "embeddedExpression">
 >(path: AstPath<T>, print: JavaPrintFn, beginKey: C, midKey: C, endKey: C) {
-  const { children } = path.node;
   const begin = call(path, ({ node }) => node.image, beginKey);
   const mids = map(path, ({ node }) => node.image, midKey);
   const end = call(path, ({ node }) => node.image, endKey);

packages/prettier-plugin-java/src/printers/helpers.ts

@@ -122,10 +122,9 @@ export function call<
 >(
   path: AstPath<T>,
   callback: MapCallback<IndexValue<IndexValue<T, "children">, P>, U>,
-  child: P,
-  index = 0
+  child: P
 ) {
-  return path.map(callback, "children", child)[index];
+  return path.map(callback, "children", child)[0];
 }
 
 export function each<
@@ -318,7 +317,7 @@ export function printClassType(
       const node = children[child]![childIndex];
       const next = array.at(index + 1);
       const nextNode = next && children[next.child]![next.index];
-      const docs = [call(path, print, child, childIndex)];
+      const docs = [path.call(print, "children", child, childIndex)];
       if (nextNode) {
         if (isNonTerminal(node)) {
           docs.push(node.name === "annotation" ? " " : ".");

packages/prettier-plugin-java/test/unit-test/if/_input.java

@@ -40,4 +40,47 @@ public void ifElseIfElseIfElse(boolean one, boolean two, boolean three) {
     }
   }
 
+  void longIfElseChain() {
+    if (1) {
+      // 1
+    } else if (2) {
+      // 2
+    } else if (3) {
+      // 3
+    } else if (4) {
+      // 4
+    } else if (5) {
+      // 5
+    } else if (6) {
+      // 6
+    } else if (7) {
+      // 7
+    } else if (8) {
+      // 8
+    } else if (9) {
+      // 9
+    } else if (10) {
+      // 10
+    } else if (11) {
+      // 11
+    } else if (12) {
+      // 12
+    } else if (13) {
+      // 13
+    } else if (14) {
+      // 14
+    } else if (15) {
+      // 15
+    } else if (16) {
+      // 16
+    } else if (17) {
+      // 17
+    } else if (18) {
+      // 18
+    } else if (19) {
+      // 19
+    } else if (20) {
+      // 20
+    }
+  }
 }

packages/prettier-plugin-java/test/unit-test/if/_output.java

@@ -39,4 +39,48 @@ public void ifElseIfElseIfElse(boolean one, boolean two, boolean three) {
       System.out.println("not on or two or three");
     }
   }
+
+  void longIfElseChain() {
+    if (1) {
+      // 1
+    } else if (2) {
+      // 2
+    } else if (3) {
+      // 3
+    } else if (4) {
+      // 4
+    } else if (5) {
+      // 5
+    } else if (6) {
+      // 6
+    } else if (7) {
+      // 7
+    } else if (8) {
+      // 8
+    } else if (9) {
+      // 9
+    } else if (10) {
+      // 10
+    } else if (11) {
+      // 11
+    } else if (12) {
+      // 12
+    } else if (13) {
+      // 13
+    } else if (14) {
+      // 14
+    } else if (15) {
+      // 15
+    } else if (16) {
+      // 16
+    } else if (17) {
+      // 17
+    } else if (18) {
+      // 18
+    } else if (19) {
+      // 19
+    } else if (20) {
+      // 20
+    }
+  }
 }