Add diagnostic for array type

Author: kimdv

Sources/SwiftParser/Types.swift

@@ -1045,7 +1045,21 @@ extension Parser {
         )
       )
     } else {
-      return self.parseType()
+      var result = self.parseType()
+      if self.at(.rightSquareBracket) {
+        let (unexpectedBeforeRSquareBracket, rightSquareBracket) = self.expect(.rightSquareBracket)
+        result = RawTypeSyntax(
+          RawArrayTypeSyntax(
+            leftSquareBracket: missingToken(.leftSquareBracket),
+            elementType: result,
+            unexpectedBeforeRSquareBracket,
+            rightSquareBracket: rightSquareBracket,
+            arena: self.arena
+          )
+        )
+      }
+
+      return result
     }
   }
 }

Sources/SwiftParserDiagnostics/ParseDiagnosticsGenerator.swift

@@ -405,6 +405,23 @@ public class ParseDiagnosticsGenerator: SyntaxAnyVisitor {
     return .visitChildren
   }
 
+  public override func visit(_ node: ArrayTypeSyntax) -> SyntaxVisitorContinueKind {
+    if shouldSkip(node) {
+      return .skipChildren
+    }
+
+    if node.leftSquareBracket.presence == .missing {
+      addDiagnostic(
+        node.leftSquareBracket,
+        .extraRightBracket,
+        fixIts: [.init(message: InsertFixIt(tokenToBeInserted: node.leftSquareBracket), changes: .makePresent(node.leftSquareBracket))],
+        handledNodes: [node.leftSquareBracket.id]
+      )
+    }
+
+    return .visitChildren
+  }
+
   public override func visit(_ node: AttributeSyntax) -> SyntaxVisitorContinueKind {
     if shouldSkip(node) {
       return .skipChildren

Sources/SwiftParserDiagnostics/ParserDiagnosticMessages.swift

@@ -131,6 +131,9 @@ extension DiagnosticMessage where Self == StaticParserError {
   public static var expectedSequenceExpressionInForEachLoop: Self {
     .init("expected Sequence expression for for-each loop")
   }
+  public static var extraRightBracket: Self {
+    .init("unexpected ']' in type; did you mean to write an array type?")
+  }
   public static var initializerInPattern: Self {
     .init("unexpected initializer in pattern; did you mean to use '='?")
   }
@@ -527,6 +530,14 @@ extension FixItMessage where Self == StaticParserFixIt {
   }
 }
 
+public struct InsertFixIt: ParserFixIt {
+  public let tokenToBeInserted: TokenSyntax
+
+  public var message: String {
+    "insert '\(tokenToBeInserted.text)'"
+  }
+}
+
 public struct MoveTokensAfterFixIt: ParserFixIt {
   /// The token that should be moved
   public let movedTokens: [TokenSyntax]

Tests/SwiftParserTest/translated/RecoveryTests.swift

@@ -1084,87 +1084,27 @@ final class RecoveryTests: XCTestCase {
     )
   }
 
-  func testRecovery98a() {
-    assertParse(
-      """
-      let a1: Swift.Int1️⃣]
-      """,
-      diagnostics: [
-        DiagnosticSpec(message: "extraneous code ']' at top level")
-      ]
-    )
-  }
-
-  func testRecovery98b() {
-    assertParse(
-      """
-      let a2: Set<Int1️⃣]>
-      """,
-      diagnostics: [
-        DiagnosticSpec(message: "expected '>' to end generic argument clause"),
-        DiagnosticSpec(message: "extraneous code ']>' at top level"),
-      ]
-    )
-  }
-
-  func testRecovery98c() {
-    assertParse(
-      """
-      let a3: Set<Int>1️⃣]
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 4: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 11 - 11 = '['
-        DiagnosticSpec(message: "extraneous code ']' at top level")
-      ]
-    )
-  }
-
-  func testRecovery98d() {
-    assertParse(
-      """
-      let a4: Int1️⃣]?
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 5: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 11 - 11 = '['
-        DiagnosticSpec(message: "extraneous code ']?' at top level")
-      ]
-    )
-  }
-
-  func testRecovery98e() {
-    assertParse(
-      """
-      let a5: Int?1️⃣]
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 6: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 11 - 11 = '['
-        DiagnosticSpec(message: "extraneous code ']' at top level")
-      ]
-    )
-  }
-
-  func testRecovery98f() {
-    assertParse(
-      """
-      let a6: [Int]1️⃣]
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 7: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 11 - 11 = '['
-        DiagnosticSpec(message: "extraneous code ']' at top level")
-      ]
-    )
-  }
-
-  func testRecovery98g() {
-    assertParse(
-      """
-      let a7: [String: Int]1️⃣]
-      """,
-      diagnostics: [
-        // TODO: Old parser expected error on line 8: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 11 - 11 = '['
-        DiagnosticSpec(message: "extraneous code ']' at top level")
-      ]
-    )
+  func testRecovery98() {
+    let testCases: [UInt: (testCase: String, fixedSource: String)] = [
+      #line: ("let a1: 1️⃣Swift.Int]", "let a1: [Swift.Int]"),
+      #line: ("let a2: Set<1️⃣Int]>", "let a2: Set<[Int]>"),
+      #line: ("let a3: 1️⃣Set<Int>]", "let a3: [Set<Int>]"),
+      #line: ("let a4: 1️⃣Int]?", "let a4: [Int]?"),
+      #line: ("let a5: 1️⃣Int?]", "let a5: [Int?]"),
+      #line: ("let a6: 1️⃣[Int]]", "let a6: [[Int]]"),
+      #line: ("let a7: [String: 1️⃣Int]]", "let a7: [[String: Int]]"),
+    ]
+
+    for (line, testCase) in testCases {
+      assertParse(
+        testCase.testCase,
+        diagnostics: [
+          DiagnosticSpec(message: "unexpected ']' in type; did you mean to write an array type?", fixIts: ["insert '['"], line: line)
+        ],
+        fixedSource: testCase.fixedSource,
+        line: line
+      )
+    }
   }
 
   func testRecovery99() {
@@ -1198,7 +1138,7 @@ final class RecoveryTests: XCTestCase {
         func foo() -> Int1️⃣[ {
           return [0]
         }  2️⃣
-        func bar() -> Int3️⃣] {
+        func bar() -> 3️⃣Int] {
           return [0]
         }
       4️⃣}
@@ -1207,7 +1147,7 @@ final class RecoveryTests: XCTestCase {
         DiagnosticSpec(locationMarker: "1️⃣", message: "expected '}' to end struct"),
         DiagnosticSpec(locationMarker: "2️⃣", message: "expected ']' to end array"),
         // TODO: Old parser expected error on line 5: unexpected ']' in type; did you mean to write an array type?, Fix-It replacements: 17 - 17 = '['
-        DiagnosticSpec(locationMarker: "3️⃣", message: "unexpected code ']' in function"),
+        DiagnosticSpec(locationMarker: "3️⃣", message: "unexpected ']' in type; did you mean to write an array type?"),
         DiagnosticSpec(locationMarker: "4️⃣", message: "extraneous brace at top level"),
       ]
     )