Merge pull request #921 from ahoppen/merge-main-6.1-2025-02-04

Merge `main` into `release/6.1`

Author: ahoppen

Documentation/Configuration.md

@@ -137,11 +137,40 @@ top-level keys and values:
 
 ---
 
-## FIXME: fileScopedDeclarationPrivacy
+## `fileScopedDeclarationPrivacy`
+**type:** object
+
+**description:** Declarations at file scope with effective private access should be consistently declared as either `fileprivate` or `private`, determined by configuration.
+
+- `accessLevel` _(string)_: The formal access level to use when encountering a file-scoped declaration with effective private access. Allowed values are `private` and `fileprivate`.
+
+**default:** `{ "accessLevel" : "private" }`  
 
 ---
 
-### FIXME: indentSwitchCaseLabels
+### `indentSwitchCaseLabels`
+**type:** boolean
+
+**description:** Determines if `case` statements should be indented compared to the containing `switch` block.
+
+When `false`, the correct form is:
+```swift
+switch someValue {
+case someCase:
+  someStatement
+...
+}
+```
+When `true`, the correct form is:
+```swift
+switch someValue {
+  case someCase:
+    someStatement
+  ...
+}
+```
+
+**default:** `false`
 
 ---
 
@@ -154,7 +183,14 @@ top-level keys and values:
 
 ---
 
-### FIXME: noAssignmentInExpressions
+### `noAssignmentInExpressions`
+**type:** object
+
+**description:** Assignment expressions must be their own statements. Assignment should not be used in an expression context that expects a `Void` value. For example, assigning a variable within a `return` statement existing a `Void` function is prohibited.
+
+- `allowedFunctions` _(strings array)_: A list of function names where assignments are allowed to be embedded in expressions that are passed as parameters to that function.
+
+**default:** `{ "allowedFunctions" : ["XCTAssertNoThrow"] }`
 
 ---
 
@@ -167,7 +203,51 @@ top-level keys and values:
 
 ---
 
-### FIXME: reflowMultilineStringLiterals
+### `reflowMultilineStringLiterals`
+**type:** `string`
+
+**description:** Determines how multiline string literals should reflow when formatted.
+
+- `never`: Never reflow multiline string literals.
+- `onlyLinesOverLength`: Reflow lines in string literal that exceed the maximum line length.
+For example with a line length of 10:
+```swift
+"""
+an escape\
+ line break
+a hard line break
+"""
+```
+will be formatted as:
+```swift
+"""
+an esacpe\
+ line break
+a hard \
+line break
+"""
+```
+- `always`: Always reflow multiline string literals, this will ignore existing escaped newlines in the literal and reflow each line. Hard linebreaks are still respected.
+For example, with a line length of 10:
+```swift
+"""
+one \
+word \
+a line.
+this is too long.
+"""
+```
+will be formatted as:
+```swift
+"""
+one word \
+a line.
+this is \
+too long.
+"""
+```
+
+**default:** `"never"`
 
 ---
 

Sources/SwiftFormat/PrettyPrint/PrettyPrintBuffer.swift

@@ -119,18 +119,21 @@ struct PrettyPrintBuffer {
     consecutiveNewlineCount = 0
     pendingSpaces = 0
 
-    // In case of comments, we may get a multi-line string.
-    // To account for that case, we need to correct the lineNumber count.
-    // The new column is only the position within the last line.
-    let lines = text.split(separator: "\n")
-    lineNumber += lines.count - 1
-    if lines.count > 1 {
-      // in case we have inserted new lines, we need to reset the column
-      column = lines.last?.count ?? 0
+    // In case of comments, we may get a multi-line string. To account for that case, we need to correct the
+    // `lineNumber` count. The new `column` is the position within the last line.
+
+    var lastNewlineIndex: String.Index? = nil
+    for i in text.utf8.indices {
+      if text.utf8[i] == UInt8(ascii: "\n") {
+        lastNewlineIndex = i
+        lineNumber += 1
+      }
+    }
+
+    if let lastNewlineIndex {
+      column = text.distance(from: text.utf8.index(after: lastNewlineIndex), to: text.endIndex)
     } else {
-      // in case it is an end of line comment or a single line comment,
-      // we just add to the current column
-      column += lines.last?.count ?? 0
+      column += text.count
     }
   }
 

Sources/SwiftFormat/PrettyPrint/WhitespaceLinter.swift

@@ -339,9 +339,16 @@ public class WhitespaceLinter {
     startingAt offset: Int,
     in data: [UTF8.CodeUnit]
   ) -> ArraySlice<UTF8.CodeUnit> {
+    func isWhitespace(_ char: UTF8.CodeUnit) -> Bool {
+      switch char {
+      case UInt8(ascii: " "), UInt8(ascii: "\n"), UInt8(ascii: "\t"), UInt8(ascii: "\r"), /*VT*/ 0x0B, /*FF*/ 0x0C:
+        return true
+      default:
+        return false
+      }
+    }
     guard
-      let whitespaceEnd =
-        data[offset...].firstIndex(where: { !UnicodeScalar($0).properties.isWhitespace })
+      let whitespaceEnd = data[offset...].firstIndex(where: { !isWhitespace($0) })
     else {
       return data[offset..<data.endIndex]
     }

Sources/swift-format/Frontend/Frontend.swift

@@ -97,7 +97,23 @@ class Frontend {
 
   /// Runs the linter or formatter over the inputs.
   final func run() {
-    if lintFormatOptions.paths.isEmpty {
+    if lintFormatOptions.paths == ["-"] {
+      processStandardInput()
+    } else if lintFormatOptions.paths.isEmpty {
+      diagnosticsEngine.emitWarning(
+        """
+        Running swift-format without input paths is deprecated and will be removed in the future.
+
+        Please update your invocation to do either of the following:
+
+        - Pass `-` to read from stdin (e.g., `cat MyFile.swift | swift-format -`).
+        - Pass one or more paths to Swift source files or directories containing
+          Swift source files. When passing directories, make sure to include the
+          `--recursive` flag.
+
+        For more information, use the `--help` option.
+        """
+      )
       processStandardInput()
     } else {
       processURLs(

Sources/swift-format/Subcommands/LintFormatOptions.swift

@@ -108,7 +108,7 @@ struct LintFormatOptions: ParsableArguments {
   var experimentalFeatures: [String] = []
 
   /// The list of paths to Swift source files that should be formatted or linted.
-  @Argument(help: "Zero or more input filenames.")
+  @Argument(help: "Zero or more input filenames. Use `-` for stdin.")
   var paths: [String] = []
 
   @Flag(help: .hidden) var debugDisablePrettyPrint: Bool = false

Tests/SwiftFormatTests/PrettyPrint/LineNumbersTests.swift

@@ -81,4 +81,38 @@ final class LineNumbersTests: PrettyPrintTestCase {
       ]
     )
   }
+
+  func testCharacterVsCodepoint() {
+    let input =
+      """
+      let fo = 1  // 🤥
+
+      """
+
+    assertPrettyPrintEqual(
+      input: input,
+      expected: input,
+      linelength: 16,
+      whitespaceOnly: true,
+      findings: []
+    )
+  }
+
+  func testCharacterVsCodepointMultiline() {
+    let input =
+      #"""
+      /// This is a multiline
+      /// comment that is in 🤥
+      /// fact perfectly sized
+
+      """#
+
+    assertPrettyPrintEqual(
+      input: input,
+      expected: input,
+      linelength: 25,
+      whitespaceOnly: true,
+      findings: []
+    )
+  }
 }