Keep blank line between different import groups

blink/internal/fixer/rules/no_blank_line_between_imports.go

@@ -46,6 +46,10 @@ func (NoBlankLineBetweenImports) Fix(s *tokens.Stream) bool {
 		if prev < 0 || s.At(prev).Kind != token.Punct || s.At(prev).Value != ";" {
 			continue
 		}
+		// keep the blank line between different import groups, e.g. class and "use function"
+		if importType(s, useIndex) != importType(s, uses[k-1]) {
+			continue
+		}
 		ws := useIndex - 1
 		if ws < 0 || s.At(ws).Kind != token.Whitespace {
 			continue
@@ -58,3 +62,17 @@ func (NoBlankLineBetweenImports) Fix(s *tokens.Stream) bool {
 	}
 	return changed
 }
+
+// importType classifies an import "use" as "function", "const" or "class".
+func importType(s *tokens.Stream, useIndex int) string {
+	j := skipWhitespace(s, useIndex+1)
+	if j < s.Len() {
+		switch strings.ToLower(s.At(j).Value) {
+		case "function":
+			return "function"
+		case "const":
+			return "const"
+		}
+	}
+	return "class"
+}

blink/internal/fixer/rules/no_blank_line_between_imports_test.go

@@ -21,4 +21,15 @@ func TestNoBlankLineBetweenImports(t *testing.T) {
 	if _, changed := apply(t, f, "<?php\n$f = function () use ($a) {};\n\n$g = function () use ($b) {};\n"); changed {
 		t.Fatal("closure use must be ignored")
 	}
+
+	// blank line between different import groups stays; within a group it collapses
+	got, changed = apply(t, f, "<?php\nnamespace X;\n\nuse A\\B;\n\nuse C\\D;\n\nuse function A\\first;\n\nuse function A\\second;\n\nuse const A\\FIRST;\n\nuse E\\F;\nclass Y {}\n")
+	if want := "<?php\nnamespace X;\n\nuse A\\B;\nuse C\\D;\n\nuse function A\\first;\nuse function A\\second;\n\nuse const A\\FIRST;\n\nuse E\\F;\nclass Y {}\n"; !changed || got != want {
+		t.Fatalf("groups: changed=%v got=%q", changed, got)
+	}
+
+	// tight class group followed by a function import: no-op, the group gap stays
+	if _, changed := apply(t, f, "<?php\nnamespace X;\n\nuse A\\B;\nuse C\\D;\n\nuse function A\\first;\n"); changed {
+		t.Fatal("distinct import groups must be a no-op")
+	}
 }

packages/coding-standard/src/Fixer/Spacing/NoBlankLineBetweenImportsFixer.php

@@ -8,6 +8,7 @@
 use PhpCsFixer\FixerDefinition\CodeSample;
 use PhpCsFixer\FixerDefinition\FixerDefinition;
 use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
+use PhpCsFixer\Tokenizer\CT;
 use PhpCsFixer\Tokenizer\Token;
 use PhpCsFixer\Tokenizer\Tokens;
 use PhpCsFixer\Tokenizer\TokensAnalyzer;
@@ -26,7 +27,7 @@ final class NoBlankLineBetweenImportsFixer extends AbstractSymplifyFixer impleme
 
     public function getDefinition(): FixerDefinitionInterface
     {
-        return new FixerDefinition(self::ERROR_MESSAGE, [new CodeSample("<?php\nuse Foo\\Bar;\n\nuse function Foo\\baz;\n")]);
+        return new FixerDefinition(self::ERROR_MESSAGE, [new CodeSample("<?php\nuse Foo\\Bar;\n\nuse Foo\\Baz;\n")]);
     }
 
     // run after OrderedImportsFixer, before BlankLineBetweenImportGroupsFixer
@@ -67,6 +68,11 @@ public function fix(SplFileInfo $fileInfo, Tokens $tokens): void
                 continue;
             }
 
+            // keep the blank line between different import groups, e.g. class and "use function"
+            if ($this->resolveImportType($tokens, $useIndex) !== $this->resolveImportType($tokens, $useIndexes[$i - 1])) {
+                continue;
+            }
+
             $whitespaceIndex = $useIndex - 1;
             if (! $tokens[$whitespaceIndex]->isWhitespace()) {
                 continue;
@@ -79,4 +85,25 @@ public function fix(SplFileInfo $fileInfo, Tokens $tokens): void
             $tokens[$whitespaceIndex] = new Token([T_WHITESPACE, $lineEnding]);
         }
     }
+
+    /**
+     * @param Tokens<Token> $tokens
+     */
+    private function resolveImportType(Tokens $tokens, int $useIndex): string
+    {
+        $nextIndex = $tokens->getNextMeaningfulToken($useIndex);
+        if ($nextIndex === null) {
+            return 'class';
+        }
+
+        if ($tokens[$nextIndex]->isGivenKind(CT::T_FUNCTION_IMPORT)) {
+            return 'function';
+        }
+
+        if ($tokens[$nextIndex]->isGivenKind(CT::T_CONST_IMPORT)) {
+            return 'const';
+        }
+
+        return 'class';
+    }
 }

packages/coding-standard/tests/Fixer/Spacing/NoBlankLineBetweenImportsFixer/Fixture/keep_blank_line_between_import_groups.php.inc

@@ -0,0 +1,41 @@
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Spacing\NoBlankLineBetweenImportsFixer\Fixture;
+
+use Foo\Bar;
+
+use Foo\Baz;
+
+use function Foo\first;
+
+use function Foo\second;
+
+use const Foo\FIRST;
+
+use Foo\Qux;
+
+class KeepBlankLineBetweenImportGroups
+{
+}
+
+?>
+-----
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Spacing\NoBlankLineBetweenImportsFixer\Fixture;
+
+use Foo\Bar;
+use Foo\Baz;
+
+use function Foo\first;
+use function Foo\second;
+
+use const Foo\FIRST;
+
+use Foo\Qux;
+
+class KeepBlankLineBetweenImportGroups
+{
+}
+
+?>