fix(match): Support empty lines and comments in match expressions (closes #1956)

src/printer.js

@@ -53,6 +53,7 @@ const {
  normalizeMagicMethodName,
  getNextNonSpaceNonCommentCharacterIndex,
  isNextLineEmpty,
+ isPreviousLineEmpty,
 } = require("./util");
 
 function isMinVersion(actualVersion, requiredVersion) {
@@ -2886,27 +2887,59 @@ function printNode(path, options, print) {
  return path.call(print, "name");
  }
  case "match": {
+ const lastArmIndex = node.arms.length - 1;
  const arms = path.map((armPath, armIdx) => {
+ const armNode = armPath.getValue();
+
+ const maybeLeadingComment = comments.hasLeadingComment(armNode)
+ ? [comments.printComments(armNode.leadingComments, options), hardline]
+ : [];
+ const maybeTrailingComma =
+ armIdx < lastArmIndex || options.trailingCommaPHP ? "," : "";
+ const maybeTrailingComment = comments.hasTrailingComment(armNode)
+ ? [
+ " ",
+ comments.printComments(
+ armNode.comments.filter((c) => c.trailing),
+ options
+ ),
+ ]
+ : [];
+
  const conds =
- armPath.getValue().conds === null
+ armNode.conds === null
  ? "default"
  : armPath.map(
  (condPath, condIdx) =>
  [",", line, print(condPath)].slice(condIdx === 0 ? 2 : 0),
  "conds"
  );
  const body = armPath.call(print, "body");
+ const maybeEmptyLineBetweenArms =
+ armIdx > 0 &&
+ isPreviousLineEmpty(options.originalText, armNode, options)
+ ? hardline
+ : "";
+
  return [
- ",",
+ "",
  hardline,
- group([group([conds, indent(line)]), "=> ", body]),
+ maybeEmptyLineBetweenArms,
+ ...maybeLeadingComment,
+ group([
+ group([conds, indent(line)]),
+ "=> ",
+ body,
+ maybeTrailingComma,
+ ...maybeTrailingComment,
+ ]),
  ].slice(armIdx > 0 ? 0 : 1);
  }, "arms");
  return group([
  "match (",
  group([softline, indent(path.call(print, "cond")), softline]),
  ") {",
- group(indent([...arms, options.trailingCommaPHP ? ifBreak(",") : ""])),
+ group(indent([...arms])),
  " ",
  softline,
  "}",

tests/comments/__snapshots__/jsfmt.spec.js.snap

@@ -4824,6 +4824,57 @@ list(
 ================================================================================
 `;
 
+exports[`match.php 1`] = `
+====================================options=====================================
+parsers: ["php"]
+printWidth: 80
+ | printWidth
+=====================================input======================================
+<?php
+
+$withComments = match($v) {
+
+ // first comment
+
+ 'a' => 1,
+
+
+
+ /*
+ * second comment
+ */
+
+
+
+ 'b' => 2,
+ // leading comment ...
+ 'c' => 3, /* ... and trailing comment */
+ 'd' // fourth comment
+ => 4,
+ default => null // final comment
+};
+
+=====================================output=====================================
+<?php
+
+$withComments = match ($v) {
+ // first comment
+ "a" => 1,
+
+ /*
+ * second comment
+ */
+ "b" => 2,
+ // leading comment ...
+ "c" => 3, /* ... and trailing comment */
+ "d" // fourth comment
+ => 4,
+ default => null, // final comment
+};
+
+================================================================================
+`;
+
 exports[`method.php 1`] = `
 ====================================options=====================================
 parsers: ["php"]

tests/comments/match.php

@@ -0,0 +1,23 @@
+<?php
+
+$withComments = match($v) {
+
+ // first comment
+
+ 'a' => 1,
+
+
+
+ /*
+ * second comment
+ */
+
+
+
+ 'b' => 2,
+ // leading comment ...
+ 'c' => 3, /* ... and trailing comment */
+ 'd' // fourth comment
+ => 4,
+ default => null // final comment
+};

tests/match/__snapshots__/jsfmt.spec.js.snap

@@ -52,6 +52,20 @@ $extraLongMatch = match($a) {
  'cd' => [],
  default => [],
 };
+
+// Whitespace in match expressions is handled like in function/method arguments:
+// - none above the first arm or below the last arm
+// - empty lines are preserved between arms
+// - multiple empty lines are collapsed into one
+match ($a) {
+
+ 'a' => 1,
+
+
+ 'b' => 2
+
+};
+
 =====================================output=====================================
 <?php
 
@@ -124,6 +138,16 @@ $extraLongMatch = match ($a) {
  default => []
 };
 
+// Whitespace in match expressions is handled like in function/method arguments:
+// - none above the first arm or below the last arm
+// - empty lines are preserved between arms
+// - multiple empty lines are collapsed into one
+match ($a) {
+ "a" => 1,
+
+ "b" => 2
+};
+
 ================================================================================
 `;
 
@@ -179,6 +203,20 @@ $extraLongMatch = match($a) {
  'cd' => [],
  default => [],
 };
+
+// Whitespace in match expressions is handled like in function/method arguments:
+// - none above the first arm or below the last arm
+// - empty lines are preserved between arms
+// - multiple empty lines are collapsed into one
+match ($a) {
+
+ 'a' => 1,
+
+
+ 'b' => 2
+
+};
+
 =====================================output=====================================
 <?php
 
@@ -251,5 +289,15 @@ $extraLongMatch = match ($a) {
  default => [],
 };
 
+// Whitespace in match expressions is handled like in function/method arguments:
+// - none above the first arm or below the last arm
+// - empty lines are preserved between arms
+// - multiple empty lines are collapsed into one
+match ($a) {
+ "a" => 1,
+
+ "b" => 2,
+};
+
 ================================================================================
 `;

tests/match/match.php

@@ -41,4 +41,17 @@
  => 'some really long value in the return part of the match statement',
  'cd' => [],
  default => [],
-};
+};
+
+// Whitespace in match expressions is handled like in function/method arguments:
+// - none above the first arm or below the last arm
+// - empty lines are preserved between arms
+// - multiple empty lines are collapsed into one
+match ($a) {
+
+ 'a' => 1,
+
+
+ 'b' => 2
+
+};