Fix manipulating GitHub links that are already in markdown link form (#…

…166)

* fix manipulating already-linked texts

* fix range check + modify the test to cover

Lambdas/GHHooks/Extensions/String+Document.swift

@@ -27,7 +27,26 @@ extension String {
             /(?<number>\d+)
         /#
         let withModifiedLinks = self.replacing(regex) { match in
-            "[\(match.output.org)/\(match.output.repo)#\(match.output.number)](\(self[match.range]))"
+            let current = self[match.range]
+            /// `match.output` is a `Range<Index>` which means it's `..<`.
+            /// So the character at `index == upperBound` is not part of the match.
+            if match.range.upperBound < self.endIndex,
+               /// `offsetBy: 2` is guaranteed to exist because the string must contain
+               /// `https` based on the regex above, so it has more length than 3.
+               match.range.lowerBound > self.index(self.startIndex, offsetBy: 2) {
+                /// All 3 indexes below are guaranteed to exist based on the range check above.
+                let before = self.index(before: match.range.lowerBound)
+                let beforeBefore = self.index(before: before)
+                /// Is surrounded like `STR` in `](STR)` or not
+                let isSurroundedInSomePuncs = self[beforeBefore] == "]" &&
+                self[before] == "(" &&
+                self[match.range.upperBound] == ")"
+                /// If it's surrounded in the punctuations above, it
+                /// might already be a link, so don't manipulate it.
+                if isSurroundedInSomePuncs { return current }
+            }
+            let output = match.output
+            return "[\(output.org)/\(output.repo)#\(output.number)](\(current))"
         }
 
         /// Remove all HTML elements and all links lacking a destination; they don't look good in Discord.

Tests/PennyTests/Tests/GHHooksTests.swift

@@ -506,9 +506,9 @@ class GHHooksTests: XCTestCase {
         /// Test modifying GitHub links
         do {
             let text = """
-            Final stage of Vapor’s `Sendable` journey as `Request` is now `Sendable` at https://github.com/swift-server/swiftly/pull/9.
+            https://github.com/swift-server/swiftly/pull/9Final stage of Vapor’s `Sendable` journey as `Request` is now [#40](https://github.com/swift-server/swiftly/pull/9) `Sendable` at https://github.com/swift-server/swiftly/pull/9.
 
-            There should https://github.com/vapor-bad-link/issues/44 be no more `Sendable` warnings in Vaporhttps://github.com/vapor/penny-bot/issues/98, even with complete concurrency checking turned on.
+            There should https://github.com/vapor-bad-link/issues/44 be no more `Sendable` warnings in Vapor https://github.com/vapor/penny-bot/issues/98, even with complete concurrency checking turned on.](https://github.com/vapor/penny-bot/issues/98
             """
 
             let formatted = text.formatMarkdown(
@@ -518,9 +518,9 @@ class GHHooksTests: XCTestCase {
             )
 
             XCTAssertMultilineStringsEqual(formatted, """
-            Final stage of Vapor’s `Sendable` journey as `Request` is now `Sendable` at [swift-server/swiftly#9](https://github.com/swift-server/swiftly/pull/9).
+            [swift-server/swiftly#9](https://github.com/swift-server/swiftly/pull/9)Final stage of Vapor’s `Sendable` journey as `Request` is now [#40](https://github.com/swift-server/swiftly/pull/9) `Sendable` at [swift-server/swiftly#9](https://github.com/swift-server/swiftly/pull/9).
 
-            There should https://github.com/vapor-bad-link/issues/44 be no more `Sendable` warnings in Vapor[vapor/penny-bot#98](https://github.com/vapor/penny-bot/issues/98), even with complete concurrency checking turned on.
+            There should https://github.com/vapor-bad-link/issues/44 be no more `Sendable` warnings in Vapor [vapor/penny-bot#98](https://github.com/vapor/penny-bot/issues/98), even with complete concurrency checking turned on.]([vapor/penny-bot#98](https://github.com/vapor/penny-bot/issues/98)
             """)
         }
     }