fix: break long nested statements

Author: jtkiesel

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

@@ -1,22 +1,3 @@
-import { builders } from "prettier/doc";
-import { concat, dedent, group, indent, join } from "./prettier-builder.js";
-import { printTokenWithComments } from "./comments/format-comments.js";
-import {
-  hasLeadingLineComments,
-  hasTrailingLineComments
-} from "./comments/comments-utils.js";
-import {
-  displaySemicolon,
-  getBlankLinesSeparator,
-  isStatementEmptyStatement,
-  putIntoBraces,
-  rejectAndConcat,
-  rejectAndJoin,
-  rejectAndJoinSeps,
-  rejectSeparators,
-  sortModifiers
-} from "./printer-utils.js";
-import { BaseCstPrettierPrinter } from "../base-cst-printer.js";
 import {
   AssertStatementCtx,
   BasicForStatementCtx,
@@ -49,6 +30,7 @@ import {
   ResourceListCtx,
   ResourceSpecificationCtx,
   ReturnStatementCtx,
+  StatementCstNode,
   StatementCtx,
   StatementExpressionCtx,
   StatementExpressionListCtx,
@@ -67,6 +49,25 @@ import {
   YieldStatementCtx
 } from "java-parser";
 import { Doc } from "prettier";
+import { builders } from "prettier/doc";
+import { BaseCstPrettierPrinter } from "../base-cst-printer.js";
+import {
+  hasLeadingLineComments,
+  hasTrailingLineComments
+} from "./comments/comments-utils.js";
+import { printTokenWithComments } from "./comments/format-comments.js";
+import { concat, group, indent, join } from "./prettier-builder.js";
+import {
+  displaySemicolon,
+  getBlankLinesSeparator,
+  isStatementEmptyStatement,
+  putIntoBraces,
+  rejectAndConcat,
+  rejectAndJoin,
+  rejectAndJoinSeps,
+  rejectSeparators,
+  sortModifiers
+} from "./printer-utils.js";
 
 const { line, softline, hardline } = builders;
 
@@ -189,18 +190,11 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
 
   ifStatement(ctx: IfStatementCtx) {
     const expression = this.visit(ctx.expression);
-
-    const ifStatement = this.visit(ctx.statement[0], {
-      allowEmptyStatement: true
-    });
-    const ifSeparator = isStatementEmptyStatement(ifStatement) ? "" : " ";
+    const ifStatement = this.subStatement(ctx.statement[0]);
 
     let elsePart: Doc = "";
     if (ctx.Else !== undefined) {
-      const elseStatement = this.visit(ctx.statement[1], {
-        allowEmptyStatement: true
-      });
-      const elseSeparator = isStatementEmptyStatement(elseStatement) ? "" : " ";
+      const elseStatement = this.subStatement(ctx.statement[1], true);
 
       const elseOnSameLine =
         hasTrailingLineComments(ctx.statement[0]) ||
@@ -210,20 +204,13 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
           ? hardline
           : " ";
 
-      elsePart = rejectAndJoin(elseSeparator, [
-        concat([elseOnSameLine, ctx.Else[0]]),
-        elseStatement
-      ]);
+      elsePart = concat([elseOnSameLine, ctx.Else[0], elseStatement]);
     }
 
-    return rejectAndConcat([
-      rejectAndJoin(" ", [
-        ctx.If[0],
-        concat([
-          putIntoBraces(expression, softline, ctx.LBrace[0], ctx.RBrace[0]),
-          ifSeparator
-        ])
-      ]),
+    return concat([
+      ctx.If[0],
+      " ",
+      putIntoBraces(expression, softline, ctx.LBrace[0], ctx.RBrace[0]),
       ifStatement,
       elsePart
     ]);
@@ -337,32 +324,24 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
 
   whileStatement(ctx: WhileStatementCtx) {
     const expression = this.visit(ctx.expression);
-    const statement = this.visit(ctx.statement[0], {
-      allowEmptyStatement: true
-    });
-    const statementSeparator = isStatementEmptyStatement(statement) ? "" : " ";
+    const statement = this.subStatement(ctx.statement[0]);
 
-    return rejectAndJoin(" ", [
+    return concat([
       ctx.While[0],
-      rejectAndJoin(statementSeparator, [
-        putIntoBraces(expression, softline, ctx.LBrace[0], ctx.RBrace[0]),
-        statement
-      ])
+      " ",
+      putIntoBraces(expression, softline, ctx.LBrace[0], ctx.RBrace[0]),
+      statement
     ]);
   }
 
   doStatement(ctx: DoStatementCtx) {
-    const statement = this.visit(ctx.statement[0], {
-      allowEmptyStatement: true
-    });
-    const statementSeparator = isStatementEmptyStatement(statement) ? "" : " ";
-
+    const statement = this.subStatement(ctx.statement[0]);
     const expression = this.visit(ctx.expression);
 
-    return rejectAndJoin(" ", [
-      rejectAndJoin(statementSeparator, [ctx.Do[0], statement]),
+    return join(" ", [
+      concat([ctx.Do[0], statement]),
       ctx.While[0],
-      rejectAndConcat([
+      concat([
         putIntoBraces(expression, softline, ctx.LBrace[0], ctx.RBrace[0]),
         ctx.Semicolon[0]
       ])
@@ -377,26 +356,21 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
     const forInit = this.visit(ctx.forInit);
     const expression = this.visit(ctx.expression);
     const forUpdate = this.visit(ctx.forUpdate);
-    const statement = this.visit(ctx.statement[0], {
-      allowEmptyStatement: true
-    });
-    const statementSeparator = isStatementEmptyStatement(statement) ? "" : " ";
+    const statement = this.subStatement(ctx.statement[0]);
 
-    return rejectAndConcat([
-      rejectAndJoin(" ", [
-        ctx.For[0],
-        putIntoBraces(
-          rejectAndConcat([
-            forInit,
-            rejectAndJoin(line, [ctx.Semicolon[0], expression]),
-            rejectAndJoin(line, [ctx.Semicolon[1], forUpdate])
-          ]),
-          softline,
-          ctx.LBrace[0],
-          ctx.RBrace[0]
-        )
-      ]),
-      statementSeparator,
+    return concat([
+      ctx.For[0],
+      " ",
+      putIntoBraces(
+        [
+          forInit,
+          rejectAndJoin(line, [ctx.Semicolon[0], expression]),
+          rejectAndJoin(line, [ctx.Semicolon[1], forUpdate])
+        ],
+        softline,
+        ctx.LBrace[0],
+        ctx.RBrace[0]
+      ),
       statement
     ]);
   }
@@ -422,17 +396,14 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
   enhancedForStatement(ctx: EnhancedForStatementCtx) {
     const localVariableDeclaration = this.visit(ctx.localVariableDeclaration);
     const expression = this.visit(ctx.expression);
-    const statement = this.visit(ctx.statement[0], {
-      allowEmptyStatement: true
-    });
-    const statementSeparator = isStatementEmptyStatement(statement) ? "" : " ";
+    const statement = this.subStatement(ctx.statement[0]);
 
-    return rejectAndConcat([
-      rejectAndJoin(" ", [ctx.For[0], ctx.LBrace[0]]),
-      localVariableDeclaration,
-      concat([" ", ctx.Colon[0], " "]),
-      expression,
-      concat([ctx.RBrace[0], statementSeparator]),
+    return concat([
+      ctx.For[0],
+      " ",
+      ctx.LBrace[0],
+      join(" ", [localVariableDeclaration, ctx.Colon[0], expression]),
+      ctx.RBrace[0],
       statement
     ]);
   }
@@ -615,4 +586,18 @@ export class BlocksAndStatementPrettierVisitor extends BaseCstPrettierPrinter {
   variableAccess(ctx: VariableAccessCtx) {
     return this.visitSingle(ctx);
   }
+
+  private subStatement(subStatement: StatementCstNode, isElse = false) {
+    const statement = this.visit(subStatement, { allowEmptyStatement: true });
+    const isBlock =
+      subStatement.children.statementWithoutTrailingSubstatement?.[0].children
+        .block !== undefined;
+    const isElseIf = isElse && subStatement.children.ifStatement !== undefined;
+    if (isBlock || isElseIf) {
+      return [" ", statement];
+    } else if (isStatementEmptyStatement(statement)) {
+      return statement;
+    }
+    return indent([line, statement]);
+  }
 }

packages/prettier-plugin-java/test/unit-test/comments/comments-blocks-and-statements/complex/_output.java

@@ -23,9 +23,8 @@ private void myFunction(
     /* axis y */int arg2,
     /* axis z */int arg3
   ) {
-    if (arg1 == 0 && arg2 == 0 && arg == 3) throw new RuntimeException(
-      "X Y Z cannot be all 0"
-    );
+    if (arg1 == 0 && arg2 == 0 && arg == 3)
+      throw new RuntimeException("X Y Z cannot be all 0");
 
     int /*variable name is of value var */var = arg1 + arg2 + arg3;
     if /*true*/(var == 0) {
@@ -66,15 +65,17 @@ private void myFunction(
   }
 
   private synchronized void myFunction(int arg1, int arg2/*overloading*/) {
-    for (int i = 0; i < /*=*/arg1; i++) do /*dodododo*/{ //do whiles
-      //asserting
-      assert /*true*/true == true;
-      continue;
-      break/*dead code*/;
-      return/*dead code*/;
-    } /*at least one iteration !*/while (false);
+    for (int i = 0; i < /*=*/arg1; i++)
+      do /*dodododo*/{ //do whiles
+        //asserting
+        assert /*true*/true == true;
+        continue;
+        break/*dead code*/;
+        return/*dead code*/;
+      } /*at least one iteration !*/while (false);
     synchronized /*declares synchronizd statement*/(this) {
-      while /*infinite*/(true) /*stop the program*/throw new RuntimeException();
+      while /*infinite*/(true)
+        /*stop the program*/throw new RuntimeException();
     }
   }
 }

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

@@ -11,27 +11,32 @@ public void emptyStatementWithComment() {
   public void simpleForWithEmptyStatement() {
     for (;;);
 
-    for (;;) /*test*/;
+    for (;;)
+      /*test*/;
 
     for (;;);/*test*/
 
-    for (;;) /*test*/;/*test*/
+    for (;;)
+      /*test*/;/*test*/
   }
 
   public void simpleForWithEmptyStatement() {
     for (;;);
 
-    for (;;) /*test*/;
+    for (;;)
+      /*test*/;
 
     for (;;);/*test*/
 
-    for (;;) /*test*/;/*test*/
+    for (;;)
+      /*test*/;/*test*/
   }
 
   public void forEachWithEmptyStatement(List<String> list) {
     for (String str : list);
 
-    for (String str : list) /*test*/;
+    for (String str : list)
+      /*test*/;
 
     for (String str : list);/*test*/
   }
@@ -51,7 +56,8 @@ public void ifElseWithEmptyStatements() {
   }
 
   public void ifElseWithEmptyStatementsWithComments() {
-    if (test) /*test*/;
+    if (test)
+      /*test*/;
     else {
       System.out.println("one");
     }
@@ -63,7 +69,8 @@ public void ifElseWithEmptyStatementsWithComments() {
 
     if (test) {
       System.out.println("two");
-    } else /*test*/;
+    } else
+      /*test*/;
 
     if (test) {
       System.out.println("two");
@@ -72,21 +79,25 @@ public void ifElseWithEmptyStatementsWithComments() {
     if (test);
     /*test*/else;/*test*/
 
-    if (test) /*test*/;
-    else /*test*/;
+    if (test)
+      /*test*/;
+    else
+      /*test*/;
   }
 
   public void simpleWhileWithEmptyStatement(boolean one) {
     while (one);
 
-    while (one) /*test*/;
+    while (one)
+      /*test*/;
 
     while (one);/*test*/
   }
 
   public void doWhileWithEmptyStatement(boolean one) {
     do; while (one);
-    do /*test*/; while (one);
+    do
+      /*test*/; while (one);
     do; /*test*/while (one);
   }
 }

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

@@ -122,7 +122,8 @@ public void printSwitch() {
   }
 
   public void printWhile() {
-    while /*infinite*/(true) /*stop the program*/throw new RuntimeException();
+    while /*infinite*/(true)
+      /*stop the program*/throw new RuntimeException();
 
     while (
       myValue == 42 ||

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

@@ -36,4 +36,8 @@ public void continueWithIdentifier() {
     }
   }
 
+  void shouldBreakNested() {
+    for (int d = 0; d < e; d++) for (int c = 0; c < d; c++) for (int b = 0; b < c; b++) a();
+    for (D dddddddddd : eeeeeeeeee) for (C cccccccccc : dddddddddd) for (B bbbbbbbbbb : cccccccccc) aaaaaaaaaa();
+  }
 }

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

@@ -35,4 +35,15 @@ public void continueWithIdentifier() {
       System.out.println(i);
     }
   }
+
+  void shouldBreakNested() {
+    for (int d = 0; d < e; d++)
+      for (int c = 0; c < d; c++)
+        for (int b = 0; b < c; b++)
+          a();
+    for (D dddddddddd : eeeeeeeeee)
+      for (C cccccccccc : dddddddddd)
+        for (B bbbbbbbbbb : cccccccccc)
+          aaaaaaaaaa();
+  }
 }