Merge pull request swiftlang#220 from dabelknap/colon-whitespace

Demote ColonWhitespace to a lint rule

Sources/SwiftFormat/PopulatePipeline.swift

@@ -37,12 +37,6 @@ func populate(_ pipeline: Pipeline) {
       TokenSyntax.self
   )
 
-  pipeline.addFormatter(
-    ColonWhitespace.self,
-    for:
-      TokenSyntax.self
-  )
-
   pipeline.addFormatter(
     DoNotUseSemicolons.self,
     for:
@@ -274,6 +268,12 @@ func populate(_ pipeline: Pipeline) {
       TokenSyntax.self
   )
 
+  pipeline.addLinter(
+    ColonWhitespace.self,
+    for:
+      TokenSyntax.self
+  )
+
   pipeline.addLinter(
     CommaWhitespace.self,
     for:

Sources/SwiftFormatRules/ColonWhitespace.swift

@@ -22,19 +22,17 @@ import SwiftSyntax
 /// Lint: If an invalid number of spaces appear before or after a colon, a lint error is
 ///       raised.
 ///
-/// Format: All colons will have no spaces before, and a single space after.
-///
 /// - SeeAlso: https://google.github.io/swift#horizontal-whitespace
-public final class ColonWhitespace: SyntaxFormatRule {
-  public override func visit(_ token: TokenSyntax) -> Syntax {
-    guard let next = token.nextToken else { return token }
+public final class ColonWhitespace: SyntaxLintRule {
+  public override func visit(_ token: TokenSyntax) {
+    guard let next = token.nextToken else { return }
 
     if token.tokenKind == .colon,
        token.containingExprStmtOrDecl is DictionaryExprSyntax,
        next.tokenKind == .rightSquareBracket,
        token.trailingTrivia.numberOfSpaces > 0 {
       diagnose(.noSpacesAfterColon, on: token)
-      return token.withoutTrailingTrivia()
+      return
     }
 
     /// Colons own their trailing spaces, so ensure it only has 1 if there's
@@ -48,16 +46,15 @@ public final class ColonWhitespace: SyntaxFormatRule {
       if numSpaces == 0 {
         diagnose(.addSpaceAfterColon, on: token)
       }
-      return token.withOneTrailingSpace()
+      return
     }
 
     /// Otherwise, colon-adjacent tokens should have 0 spaces after.
     if next.tokenKind == .colon, token.trailingTrivia.containsSpaces,
       !(next.containingExprStmtOrDecl is TernaryExprSyntax) {
       diagnose(.noSpacesBeforeColon, on: next)
-      return token.withTrailingTrivia(token.trailingTrivia.withoutSpaces())
+      return
     }
-    return token
   }
 }
 

Tests/SwiftFormatRulesTests/ColonWhitespaceTests.swift

@@ -5,24 +5,34 @@ import XCTest
 
 public class ColonWhitespaceTests: DiagnosingTestCase {
   public func testInvalidColonWhitespace() {
-    XCTAssertFormatting(
-      ColonWhitespace.self,
-      input: """
-             let v1: Int = 0
-             let v2 : Int = 1
-             let v3 :Int = 1
-             let v4    \t: \t     Int = 1
-             let v5: [Int: String] = [: ]
-             let v6: [Int: String] = [23:  "twenty three"]
-             """,
-      expected: """
-                let v1: Int = 0
-                let v2: Int = 1
-                let v3: Int = 1
-                let v4: Int = 1
-                let v5: [Int: String] = [:]
-                let v6: [Int: String] = [23: "twenty three"]
-                """)
+    let input =
+      """
+      let v1: Int = 0
+      let v2 : Int = 1
+      let v3 :Int = 1
+      let v4    \t: \t     Int = 1
+      let v5: [Int: String] = [: ]
+      let v6: [Int: String] = [23:  "twenty three"]
+      """
+
+    performLint(ColonWhitespace.self, input: input)
+
+    // let v2 : Int = 1
+    XCTAssertDiagnosed(.noSpacesBeforeColon)
+
+    // let v3 :Int = 1
+    XCTAssertDiagnosed(.noSpacesBeforeColon)
+    XCTAssertDiagnosed(.addSpaceAfterColon)
+
+    // let v4    \t: \t     Int = 1
+    XCTAssertDiagnosed(.noSpacesBeforeColon)
+    XCTAssertDiagnosed(.removeSpacesAfterColon(count: 6))
+
+    // let v5: [Int: String] = [: ]
+    XCTAssertDiagnosed(.noSpacesAfterColon)
+
+    // let v6: [Int: String] = [23:  "twenty three"]
+    XCTAssertDiagnosed(.removeSpacesAfterColon(count: 1))
   }
 
   #if !os(macOS)