Fix versioning bug in release tooling (#8256)

* Fix versioning bug

* Cleanup approach

* Fix typo

* Fix another typo

Author: ncooke3

ReleaseTooling/Sources/FirebaseReleaser/InitializeRelease.swift

@@ -75,38 +75,19 @@ struct InitializeRelease {
       let pod = firebasePod.name
       let version = firebasePod.isBeta ? firebaseVersion + "-beta" : firebaseVersion
       if pod == "Firebase" {
-        // TODO: This then block is redundant with the updatePodspecs function above and is left
-        // until we decide to go with Swift or sed.
-        // Replace version in string like s.version = '6.9.0'
+        // TODO: This block is redundant with `updatePodspecs`. Decide to go with Swift or sed.
         guard let range = contents.range(of: "s.version") else {
           fatalError("Could not find version of Firebase pod in podspec at \(podspecFile)")
         }
-        var versionStartIndex = contents.index(range.upperBound, offsetBy: 1)
-        while contents[versionStartIndex] != "'" {
-          versionStartIndex = contents.index(versionStartIndex, offsetBy: 1)
-        }
-        var versionEndIndex = contents.index(versionStartIndex, offsetBy: 1)
-        while contents[versionEndIndex] != "'" {
-          versionEndIndex = contents.index(versionEndIndex, offsetBy: 1)
-        }
-        contents.removeSubrange(versionStartIndex ... versionEndIndex)
-        contents.insert(contentsOf: "'" + version + "'", at: versionStartIndex)
+        // Replace version in string like s.version = '6.9.0'
+        updateVersion(&contents, in: range, to: version)
+
       } else {
-        // Replace version in string like ss.dependency 'FirebaseCore', '6.3.0'
-        guard let range = contents.range(of: pod) else {
-          // This pod is not a top-level Firebase pod dependency.
-          continue
-        }
-        var versionStartIndex = contents.index(range.upperBound, offsetBy: 2)
-        while !contents[versionStartIndex].isWholeNumber {
-          versionStartIndex = contents.index(versionStartIndex, offsetBy: 1)
+        // Iterate through all the ranges of `pod`'s occurrences.
+        for range in contents.ranges(of: pod) {
+          // Replace version in string like ss.dependency 'FirebaseCore', '6.3.0'.
+          updateVersion(&contents, in: range, to: version)
         }
-        var versionEndIndex = contents.index(versionStartIndex, offsetBy: 1)
-        while contents[versionEndIndex] != "'" {
-          versionEndIndex = contents.index(versionEndIndex, offsetBy: 1)
-        }
-        contents.removeSubrange(versionStartIndex ... versionEndIndex)
-        contents.insert(contentsOf: version + "'", at: versionStartIndex)
       }
     }
     do {
@@ -116,6 +97,24 @@ struct InitializeRelease {
     }
   }
 
+  /// Update the existing version to the given version by writing to a given string using the provided range.
+  /// - Parameters:
+  ///   - contents: A reference to a String containing a version that will be updated.
+  ///   - range: The range containing a version substring that will be updated.
+  ///   - version: The version string to update to.
+  private static func updateVersion(_ contents: inout String, in range: Range<String.Index>,
+                                    to version: String) {
+    var versionStartIndex = contents.index(after: range.upperBound)
+    while !contents[versionStartIndex].isWholeNumber {
+      versionStartIndex = contents.index(after: versionStartIndex)
+    }
+    var versionEndIndex = contents.index(after: versionStartIndex)
+    while contents[versionEndIndex] != "'" {
+      versionEndIndex = contents.index(after: versionEndIndex)
+    }
+    contents.replaceSubrange(versionStartIndex ..< versionEndIndex, with: version)
+  }
+
   private static func updatePodfiles(path: URL, version: String) {
     // Update the Podfiles across the repo.
     let firestorePodfile = path.appendingPathComponent("Firestore")

ReleaseTooling/Sources/Utils/String+Utils.swift

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Foundation
+
+/// Utilities to simplify String operations.
+public extension String {
+  /// Finds and returns the ranges of all occurrences of a given string within a given range of the String, subject to given options,
+  /// using the specified locale, if any.
+  /// - Returns: An an optional array of ranges where each range corresponds to an occurence of the substring in the given string.
+  func ranges<T: StringProtocol>(of substring: T, options: CompareOptions = .literal,
+                                 locale: Locale? = nil) -> [Range<Index>] {
+    var ranges: [Range<Index>] = []
+
+    let end = endIndex
+    var searchRange = startIndex ..< end
+
+    while searchRange.lowerBound < end {
+      guard let range = self.range(
+        of: substring,
+        options: options,
+        range: searchRange,
+        locale: locale
+      )
+      else { break }
+
+      ranges.append(range)
+
+      let shiftedStart = index(range.lowerBound, offsetBy: 1)
+      searchRange = shiftedStart ..< end
+    }
+
+    return ranges
+  }
+}