From b379819cfade731d1509d3fa60632f87b52ea2e5 Mon Sep 17 00:00:00 2001
From: Matt W <436037+mlw@users.noreply.github.com>
Date: Fri, 22 Mar 2024 16:44:45 -0400
Subject: [PATCH] Overrides disabled when running tests unless explicitly
 enabled (#1312)

* Emit a log warning when overrides were applied

* Overrides now disabled in tests unless explicitly enabled

* Remove log message. Check for xctest instead of bazel env vars.

* Typo
---
 Source/common/SNTConfigurator.m | 42 ++++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/Source/common/SNTConfigurator.m b/Source/common/SNTConfigurator.m
index 334ffa5b6..829bcb524 100644
--- a/Source/common/SNTConfigurator.m
+++ b/Source/common/SNTConfigurator.m
@@ -1222,18 +1222,20 @@ - (NSRegularExpression *)expressionForPattern:(NSString *)pattern {
   return [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:NULL];
 }
 
-- (NSMutableDictionary *)readForcedConfig {
-  NSMutableDictionary *forcedConfig = [NSMutableDictionary dictionary];
-  for (NSString *key in self.forcedConfigKeyTypes) {
-    id obj = [self forcedConfigValueForKey:key];
-    forcedConfig[key] = [obj isKindOfClass:self.forcedConfigKeyTypes[key]] ? obj : nil;
-    // Create the regex objects now
-    if (self.forcedConfigKeyTypes[key] == [NSRegularExpression class]) {
-      NSString *pattern = [obj isKindOfClass:[NSString class]] ? obj : nil;
-      forcedConfig[key] = [self expressionForPattern:pattern];
-    }
-  }
+- (void)applyOverrides:(NSMutableDictionary *)forcedConfig {
+  // Overrides should only be applied under debug builds.
 #ifdef DEBUG
+  if ([[[NSProcessInfo processInfo] processName] isEqualToString:@"xctest"] &&
+      ![[[NSProcessInfo processInfo] environment] objectForKey:@"ENABLE_CONFIG_OVERRIDES"]) {
+    // By default, config overrides are not applied when running tests to help
+    // mitigate potential issues due to unexpected config values. This behavior
+    // can be overriden if desired by using the env variable: `ENABLE_CONFIG_OVERRIDES`.
+    //
+    // E.g.:
+    //   bazel test --test_env=ENABLE_CONFIG_OVERRIDES=1 ...other test args...
+    return;
+  }
+
   NSDictionary *overrides = [NSDictionary dictionaryWithContentsOfFile:kConfigOverrideFilePath];
   for (NSString *key in overrides) {
     id obj = overrides[key];
@@ -1242,13 +1244,31 @@ - (NSMutableDictionary *)readForcedConfig {
          ![obj isKindOfClass:[NSString class]])) {
       continue;
     }
+
     forcedConfig[key] = obj;
+
     if (self.forcedConfigKeyTypes[key] == [NSRegularExpression class]) {
       NSString *pattern = [obj isKindOfClass:[NSString class]] ? obj : nil;
       forcedConfig[key] = [self expressionForPattern:pattern];
     }
   }
 #endif
+}
+
+- (NSMutableDictionary *)readForcedConfig {
+  NSMutableDictionary *forcedConfig = [NSMutableDictionary dictionary];
+  for (NSString *key in self.forcedConfigKeyTypes) {
+    id obj = [self forcedConfigValueForKey:key];
+    forcedConfig[key] = [obj isKindOfClass:self.forcedConfigKeyTypes[key]] ? obj : nil;
+    // Create the regex objects now
+    if (self.forcedConfigKeyTypes[key] == [NSRegularExpression class]) {
+      NSString *pattern = [obj isKindOfClass:[NSString class]] ? obj : nil;
+      forcedConfig[key] = [self expressionForPattern:pattern];
+    }
+  }
+
+  [self applyOverrides:forcedConfig];
+
   return forcedConfig;
 }