Adding tests for String's replaceSubrange overloads for non-closed ranges

Author: austinzheng

validation-test/stdlib/String.swift

@@ -1282,5 +1282,129 @@ StringTests.test("String.decodeCString/UTF32") {
   expectEqual("foobar", actual!.result)
 }
 
+internal struct ReplaceSubrangeTest {
+  let original: String
+  let newElements: String
+  // RangeSelection is defined in CheckRangeReplaceableCollectionType
+  let rangeSelection: RangeSelection
+  let expected: String
+  let closedExpected: String?  // Expected array for closed ranges
+  let loc: SourceLoc
+
+  internal init(
+    original: String, newElements: String,
+    rangeSelection: RangeSelection, expected: String, closedExpected: String? = nil,
+    file: String = #file, line: UInt = #line
+  ) {
+    self.original = original
+    self.newElements = newElements
+    self.rangeSelection = rangeSelection
+    self.expected = expected
+    self.closedExpected = closedExpected
+    self.loc = SourceLoc(file, line, comment: "replaceSubrange() test data")
+  }
+}
+
+let replaceSubrangeTests = [
+  ReplaceSubrangeTest(
+    original: "",
+    newElements: "",
+    rangeSelection: .emptyRange,
+    expected: ""
+  ),
+  ReplaceSubrangeTest(
+    original: "",
+    newElements: "meela",
+    rangeSelection: .emptyRange,
+    expected: "meela"
+  ),
+  ReplaceSubrangeTest(
+    original: "eela",
+    newElements: "m",
+    rangeSelection: .leftEdge,
+    expected: "meela"
+  ),
+  ReplaceSubrangeTest(
+    original: "meel",
+    newElements: "a",
+    rangeSelection: .rightEdge,
+    expected: "meela"
+  ),
+  ReplaceSubrangeTest(
+    original: "a",
+    newElements: "meel",
+    rangeSelection: .leftEdge,
+    expected: "meela"
+  ),
+  ReplaceSubrangeTest(
+    original: "m",
+    newElements: "eela",
+    rangeSelection: .rightEdge,
+    expected: "meela"
+  ),
+  ReplaceSubrangeTest(
+    original: "alice",
+    newElements: "bob",
+    rangeSelection: .offsets(1, 1),
+    expected: "aboblice"
+  ),
+  ReplaceSubrangeTest(
+    original: "alice",
+    newElements: "bob",
+    rangeSelection: .offsets(1, 2),
+    expected: "abobice"
+  ),
+  ReplaceSubrangeTest(
+    original: "alice",
+    newElements: "bob",
+    rangeSelection: .offsets(1, 3),
+    expected: "abobce"
+  ),
+  ReplaceSubrangeTest(
+    original: "alice",
+    newElements: "bob",
+    rangeSelection: .offsets(1, 4),
+    expected: "abobe"
+  ),
+  ReplaceSubrangeTest(
+    original: "alice",
+    newElements: "bob",
+    rangeSelection: .offsets(1, 5),
+    expected: "abob"
+  ),
+  ReplaceSubrangeTest(
+    original: "bob",
+    newElements: "meela",
+    rangeSelection: .offsets(1, 2),
+    expected: "bmeelab"
+  ),
+]
+
+StringTests.test("String.replaceSubrange()/characters/range") {
+  for test in replaceSubrangeTests {
+    var theString = test.original
+    let c = test.original.characters
+    let rangeToReplace = test.rangeSelection.range(in: c)
+    let newCharacters : [Character] = test.newElements.characters.map { $0 }
+    theString.replaceSubrange(rangeToReplace, with: newCharacters)
+    expectEqual(
+      theString,
+      test.expected,
+      stackTrace: SourceLocStack().with(test.loc))
+  }
+}
+
+StringTests.test("String.replaceSubrange()/string/range") {
+  for test in replaceSubrangeTests {
+    var theString = test.original
+    let c = test.original.characters
+    let rangeToReplace = test.rangeSelection.range(in: c)
+    theString.replaceSubrange(rangeToReplace, with: test.newElements)
+    expectEqual(
+      theString,
+      test.expected,
+      stackTrace: SourceLocStack().with(test.loc))
+  }
+}
 
 runAllTests()