From f210b1d57397ad62502becc8a5a90791e39384a4 Mon Sep 17 00:00:00 2001
From: Nico Hinderling <NicoHinderling@users.noreply.github.com>
Date: Mon, 13 Nov 2023 11:51:35 -0800
Subject: [PATCH] Add ExcludedSnapshotPreviews support (#69)

Co-authored-by: Nicolas Hinderling <nicolashinderling@Nicolass-MacBook-Pro.local>
---
 DemoApp/DemoAppUITests/MyPreviewTest.swift    |  4 +++
 Sources/SnapshottingSwift/Snapshots.swift     | 31 ++++++++++++++++---
 Sources/SnapshottingTests/PreviewTest.m       | 11 +++++++
 .../SnapshottingTests/include/PreviewTest.h   |  2 ++
 4 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/DemoApp/DemoAppUITests/MyPreviewTest.swift b/DemoApp/DemoAppUITests/MyPreviewTest.swift
index 309a12c..531ba7e 100644
--- a/DemoApp/DemoAppUITests/MyPreviewTest.swift
+++ b/DemoApp/DemoAppUITests/MyPreviewTest.swift
@@ -19,6 +19,10 @@ class MyPreviewTest: PreviewTest {
   override func snapshotPreviews() -> [String]? {
     return nil
   }
+    
+  override func excludedSnapshotPreviews() -> [String]? {
+    return nil
+  }
 
   override func enableAccessibilityAudit() -> Bool {
     true
diff --git a/Sources/SnapshottingSwift/Snapshots.swift b/Sources/SnapshottingSwift/Snapshots.swift
index eacdce8..cd1fb06 100644
--- a/Sources/SnapshottingSwift/Snapshots.swift
+++ b/Sources/SnapshottingSwift/Snapshots.swift
@@ -136,16 +136,39 @@ class Snapshots {
     try! FileManager.default.createDirectory(at: Self.resultsDir, withIntermediateDirectories: true)
 
     let snapshotPreviews = ProcessInfo.processInfo.environment["SNAPSHOT_PREVIEWS"];
+    let excludedSnapshotPreviews = ProcessInfo.processInfo.environment["EXCLUDED_SNAPSHOT_PREVIEWS"];
+
     var previewsSet: Set<String>? = nil
     if let snapshotPreviews {
       let previewsList = try! JSONDecoder().decode([String].self, from: snapshotPreviews.data(using: .utf8)!)
       previewsSet = Set(previewsList)
     }
-    let previewTypes = findPreviews { name in
-      guard let previewsSet else { return true }
-
-      return previewsSet.contains(name)
+    var excludedPreviewsSet: Set<String>? = nil
+    if let excludedSnapshotPreviews {
+      let excludedPreviewsList = try! JSONDecoder().decode([String].self, from: excludedSnapshotPreviews.data(using: .utf8)!)
+      excludedPreviewsSet = Set(excludedPreviewsList)
     }
+      
+      let previewTypes = findPreviews { name in
+          if let previewsSet {
+              return previewsSet.contains(name)
+          } else if let excludedPreviewsSet {
+              if #available(iOS 16.0, *) {
+                  for excludedPreview in excludedPreviewsSet {
+                      do {
+                          let regex = try Regex(excludedPreview)
+                          if name.firstMatch(of: regex) != nil {
+                              return false
+                          }
+                      } catch {
+                          print("Error trying to unwrap regex for excludedSnapshotPreview (\(excludedPreview)): \(error)")
+                      }
+                  }
+              }
+
+          }
+          return true
+      }
     let json = previewTypes.map { preview in
       [
         "typeName": preview.typeName,
diff --git a/Sources/SnapshottingTests/PreviewTest.m b/Sources/SnapshottingTests/PreviewTest.m
index d954c2c..7cdcbbb 100644
--- a/Sources/SnapshottingTests/PreviewTest.m
+++ b/Sources/SnapshottingTests/PreviewTest.m
@@ -48,6 +48,10 @@ - (XCUIApplication *)getApp {
   return NULL;
 }
 
+- (NSArray<NSString *> *)excludedSnapshotPreviews {
+  return NULL;
+}
+
 - (BOOL)enableAccessibilityAudit {
   return YES;
 }
@@ -82,6 +86,13 @@ - (void)generateSnapshots {
     NSData *jsonData = [NSJSONSerialization dataWithJSONObject:previews options:nil error:nil];
     launchEnvironment[@"SNAPSHOT_PREVIEWS"] = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
   }
+    
+  NSArray *excludedPreviews = [self excludedSnapshotPreviews];
+  if (excludedPreviews) {
+    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:excludedPreviews options:nil error:nil];
+    launchEnvironment[@"EXCLUDED_SNAPSHOT_PREVIEWS"] = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
+  }
+    
   app.launchEnvironment = launchEnvironment;
   [app launch];
 
diff --git a/Sources/SnapshottingTests/include/PreviewTest.h b/Sources/SnapshottingTests/include/PreviewTest.h
index be8131b..bbe5abd 100644
--- a/Sources/SnapshottingTests/include/PreviewTest.h
+++ b/Sources/SnapshottingTests/include/PreviewTest.h
@@ -19,6 +19,8 @@
 // Elements should be the type name of the preview, like "MyModule.MyView_Previews"
 - (nullable NSArray<NSString *> *)snapshotPreviews;
 
+- (nullable NSArray<NSString *> *)excludedSnapshotPreviews;
+
 - (BOOL)enableAccessibilityAudit;
 
 - (XCUIAccessibilityAuditType)auditType API_AVAILABLE(ios(17.0));