FPPP: Support insert at start of list node (#446)

CHANGELOG.md

@@ -5,6 +5,10 @@ Version 4.0.0-dev
 
 * Fixed comment indentation in formatting-preserving pretty printer.
 
+### Added
+
+* Added support for inserting at the start of list nodes in formatting-preserving pretty printer.
+
 Version 4.0.0-alpha2 (2017-11-10)
 ---------------------------------
 

lib/PhpParser/PrettyPrinterAbstract.php

@@ -688,6 +688,10 @@ abstract class PrettyPrinterAbstract
     ) {
         $diff = $this->nodeListDiffer->diffWithReplacements($origNodes, $nodes);
 
+        /** @var Node|null $delayedAddNode Used for insertions at the start of the list */
+        $delayedAddNode = null;
+        $delayedAddInsertStr = '';
+
         $result = '';
         foreach ($diff as $i => $diffElem) {
             $diffType = $diffElem->type;
@@ -726,23 +730,46 @@ abstract class PrettyPrinterAbstract
 
                 $comments = $arrItem->getComments();
                 $origComments = $origArrItem->getComments();
-                if ($comments !== $origComments) {
-                    if ($origComments) {
-                        $commentStartPos = $origComments[0]->getTokenPos();
-                        \assert($commentStartPos >= 0);
+                $commentStartPos = $origComments ? $origComments[0]->getTokenPos() : $itemStartPos;
+                \assert($commentStartPos >= 0);
 
-                        // Remove old comments
-                        $itemStartPos = $commentStartPos;
+                $commentsChanged = $comments !== $origComments;
+                if ($commentsChanged) {
+                    // Remove old comments
+                    $itemStartPos = $commentStartPos;
+                }
+
+                if (null !== $delayedAddNode) {
+                    $result .= $this->origTokens->getTokenCode(
+                        $pos, $commentStartPos, $indentAdjustment);
+
+                    if ($delayedAddInsertStr === "\n") {
+                        $delayedAddComments = $delayedAddNode->getComments();
+                        if ($delayedAddComments) {
+                            $result .= $this->pComments($delayedAddComments) . $this->nl;
+                        }
                     }
 
-                    $result .= $this->origTokens->getTokenCode($pos, $itemStartPos, $indentAdjustment);
+                    $this->safeAppend($result, $this->p($delayedAddNode));
 
-                    if ($comments) {
-                        // Add new comments
-                        $result .= $this->pComments($comments) . $this->nl;
+                    if ($delayedAddInsertStr === "\n") {
+                        $result .= $this->nl;
+                    } else {
+                        $result .= $delayedAddInsertStr;
                     }
+
+                    $result .= $this->origTokens->getTokenCode(
+                        $commentStartPos, $itemStartPos, $indentAdjustment);
+
+                    $delayedAddNode = null;
                 } else {
-                    $result .= $this->origTokens->getTokenCode($pos, $itemStartPos, $indentAdjustment);
+                    $result .= $this->origTokens->getTokenCode(
+                        $pos, $itemStartPos, $indentAdjustment);
+                }
+
+                if ($commentsChanged && $comments) {
+                    // Add new comments
+                    $result .= $this->pComments($comments) . $this->nl;
                 }
             } else if ($diffType === DiffElem::TYPE_ADD) {
                 if (null === $insertStr) {
@@ -751,8 +778,15 @@ abstract class PrettyPrinterAbstract
                 }
 
                 if ($i === 0) {
-                    // TODO Handle insertion at the start
-                    return null;
+                    if (count($diff) === 1) {
+                        // TODO Handle insertion into empty list
+                        return null;
+                    }
+
+                    // These will be inserted at the next "replace" or "keep" element
+                    $delayedAddNode = $arrItem;
+                    $delayedAddInsertStr = $insertStr;
+                    continue;
                 }
 
                 $itemStartPos = $pos;

test/code/formatPreservation/abc1.test

@@ -89,6 +89,7 @@ call1(
 );
 -----
 <?php
+x;
 function test() {
     call1(
         $bar
@@ -98,15 +99,14 @@ call2(
     $foo
 );
 -----
-$tmp = $stmts[0]->stmts[0];
-$stmts[0]->stmts[0] = $stmts[1];
-$stmts[1] = $tmp;
-// Same test, but also prepending to $stmts, triggering fallback
-array_unshift($stmts, new Stmt\Echo_([new Scalar\LNumber(42)]));
+$tmp = $stmts[1]->stmts[0];
+$stmts[1]->stmts[0] = $stmts[2];
+$stmts[2] = $tmp;
+// Same test, but also removing first statement, triggering fallback
+array_splice($stmts, 0, 1, []);
 -----
 <?php
 
-echo 42;
 function test() {
     call2(
         $foo

test/code/formatPreservation/listInsertion.test

@@ -63,11 +63,21 @@ try {
 function test(Foo     $param1) {}
 -----
 array_unshift($stmts[0]->params, new Node\Param(new Expr\Variable('param0')));
-/* Insertion at the start not handled yet */
 -----
 <?php
 
-function test($param0, Foo     $param1)
+function test($param0, Foo     $param1) {}
+-----
+<?php
+
+function test() {}
+-----
+$stmts[0]->params[] = new Node\Param(new Expr\Variable('param0'));
+/* Insertion into empty list not handled yet */
+-----
+<?php
+
+function test($param0)
 {
 }
 -----
@@ -138,4 +148,95 @@ $stmts[0]->name->parts[0] = 'Xyz';
 -----
 <?php
 namespace
-Xyz;
+Xyz;
+-----
+<?php
+function test() {
+    $foo; $bar;
+}
+-----
+$node = new Stmt\Expression(new Expr\Variable('baz'));
+array_unshift($stmts[0]->stmts, $node);
+-----
+<?php
+function test() {
+    $baz;
+    $foo; $bar;
+}
+-----
+<?php
+function test() {
+    $foo; $bar;
+}
+-----
+$node = new Stmt\Expression(new Expr\Variable('baz'));
+$node->setAttribute('comments', [new Comment('// Test')]);
+array_unshift($stmts[0]->stmts, $node);
+-----
+<?php
+function test() {
+    // Test
+    $baz;
+    $foo; $bar;
+}
+-----
+<?php
+function test() {
+
+    // Foo bar
+    $foo; $bar;
+}
+-----
+$node = new Stmt\Expression(new Expr\Variable('baz'));
+$node->setAttribute('comments', [new Comment('// Test')]);
+array_unshift($stmts[0]->stmts, $node);
+-----
+<?php
+function test() {
+
+    // Test
+    $baz;
+    // Foo bar
+    $foo; $bar;
+}
+-----
+<?php
+function test() {
+
+    // Foo bar
+    $foo; $bar;
+}
+-----
+$node = new Stmt\Expression(new Expr\Variable('baz'));
+$node->setAttribute('comments', [new Comment('// Test')]);
+array_unshift($stmts[0]->stmts, $node);
+$stmts[0]->stmts[1]->setAttribute('comments', [new Comment('// Bar foo')]);
+-----
+<?php
+function test() {
+
+    // Test
+    $baz;
+    // Bar foo
+    $foo; $bar;
+}
+-----
+<?php
+function test() {
+
+    // Foo bar
+    $foo; $bar;
+}
+-----
+$node = new Stmt\Expression(new Expr\Variable('baz'));
+$node->setAttribute('comments', [new Comment('// Test')]);
+array_unshift($stmts[0]->stmts, $node);
+$stmts[0]->stmts[1]->setAttribute('comments', []);
+-----
+<?php
+function test() {
+
+    // Test
+    $baz;
+    $foo; $bar;
+}