Add alert if project file has no build settings

- Add NSDictionary category the checks for build settings
- Add test for new NSDictionary category
- Resolves #18

Author: dempseyatgithub

BuildSettingExtractor/BuildSettingExtractor.m

@@ -117,18 +117,28 @@ - (BOOL)extractBuildSettingsFromProject:(NSURL *)projectWrapperURL toDestination
             NSDictionary *projectSettings = [self buildSettingStringsByConfigurationForBuildConfigurationListID:buildConfigurationListID];
 
             self.buildSettingsByTarget[validatedProjectConfigName] = projectSettings;
+            
+            // Begin check that the project file has some settings
+            BOOL projectFileHasSettings = projectSettings.containsBuildSettings;
 
             // Add project targets
             for (NSDictionary *target in targets) {
                 NSString *targetName = target[@"name"];
                 buildConfigurationListID = target[@"buildConfigurationList"];
                 NSDictionary *targetSettings = [self buildSettingStringsByConfigurationForBuildConfigurationListID:buildConfigurationListID];
+                if (!projectFileHasSettings) { projectFileHasSettings = targetSettings.containsBuildSettings; }
 
                 self.buildSettingsByTarget[targetName] = targetSettings;
 
             }
 
-            [self writeConfigFilesToDestinationFolder:folderURL];
+            if (projectFileHasSettings) {
+                [self writeConfigFilesToDestinationFolder:folderURL];
+            } else {
+                [self presentErrorForNoSettingsFoundInProject: [projectWrapperURL lastPathComponent]];
+                success = NO;
+            }
+            
         }
     }
     return success;
@@ -160,6 +170,20 @@ - (void)presentErrorForNameConflictWithName:(NSString *)conflictedName validated
 
 }
 
+// Notify the user we did not find any settings in the project.
+- (void)presentErrorForNoSettingsFoundInProject:(NSString *)projectName {
+    NSString *errorDescription = [NSString stringWithFormat:@"No settings found."];
+    NSString *errorRecoverySuggestion = [NSString stringWithFormat:@"No settings were found in the project \'%@\'.\n\nThe project may already be using .xcconfig files for its build settings.\n\nNo xcconfig files will be written. ", projectName];
+    NSDictionary *errorUserInfo = @{NSLocalizedDescriptionKey:errorDescription, NSLocalizedRecoverySuggestionErrorKey: errorRecoverySuggestion};
+    
+    NSError *error = [NSError errorWithDomain:[[NSBundle mainBundle] bundleIdentifier] code:NoSettingsFoundInProjectFile userInfo:errorUserInfo];
+    
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [NSApp presentError:error];
+    });
+    
+}
+
 /* Writes an xcconfig file for each target / configuration combination to the specified directory.
  */
 - (void)writeConfigFilesToDestinationFolder:(NSURL *)destinationURL {

BuildSettingExtractor/Constants+Categories.h

@@ -12,6 +12,7 @@ typedef NS_ENUM(NSUInteger, AppErrorCodes) {
     UnsupportedXcodeVersion = 100,
     DirectoryContainsBuildConfigFiles = 101,
     ProjectSettingsNamingConflict = 102,
+    NoSettingsFoundInProjectFile = 103,
 };
 
 extern NSString *const TPSOpenDirectoryInFinder;
@@ -39,3 +40,13 @@ extern NSString *const TPSOutputFileNameSeparator;
 @interface NSString (TPS_BuildSettingAdditions)
 - (NSString *)tps_baseBuildSettingName; // Removes any conditional section of a build setting
 @end
+
+#pragma mark -
+
+@interface NSDictionary (TPS_BuildSettingAdditions)
+// Assumes that a dictionary of build settings always has NSString values
+// Returns NO if all the values in a dictionary are an empty string
+// Raises an exception if used on a dictionary with any non-NSString value
+- (BOOL)containsBuildSettings;
+@end
+

BuildSettingExtractor/Constants+Categories.m

@@ -77,4 +77,26 @@ - (NSString *)tps_baseBuildSettingName {
     return baseBuildSettingName;
 }
 
-@end
+@end
+
+#pragma mark -
+
+@implementation NSDictionary (TPS_BuildSettingAdditions)
+
+    - (BOOL)containsBuildSettings {
+        BOOL foundNonEmptyString = NO;
+        for (id value in self.allValues) {
+            if ([value isKindOfClass:[NSString class]]) {
+                if (![(NSString *)value isEqualToString:@""]) {
+                    foundNonEmptyString = YES;
+                    break;
+                }
+            } else {
+                [NSException raise:(NSInternalInconsistencyException) format:@"-containsBuildSetting is expected to be called on a dictionary with NSString values."];
+            }
+        }
+        return foundNonEmptyString;
+    }
+
+@end
+

BuildSettingExtractorTests/BuildSettingExtractorTests.m

@@ -8,6 +8,7 @@
 
 #import <XCTest/XCTest.h>
 #import "BuildSettingExtractor.h"
+#import "Constants+Categories.h"
 
 @interface NSObject (BuildSettingExtractorMethods)
 - (NSDictionary *)buildSettingsByConfigurationForConfigurations:(NSArray *)buildConfigurations;
@@ -35,4 +36,20 @@ - (void)testThreeBuildConfigurations
     XCTAssert([sharedBuildSettings isEqualToDictionary:expectedBuildSettings], @"Build settings should match");
 }
 
+- (void)testDictionaryBuildSettingsCategory
+{
+    NSDictionary *dictionaryWithBuildSettings = @{ @"Shared": @"COPY_PHASE_STRIP = NO", @"Release": @"COPY_PHASE_STRIP = NO", @"Debug": @"COPY_PHASE_STRIP = NO" };
+    XCTAssertTrue(dictionaryWithBuildSettings.containsBuildSettings);
+    
+    NSDictionary *dictionaryWithMinimalBuildSettings = @{ @"Shared": @"", @"Release": @"", @"Debug": @"COPY_PHASE_STRIP = NO" };
+    XCTAssertTrue(dictionaryWithMinimalBuildSettings.containsBuildSettings);
+
+    NSDictionary *dictionaryWithoutBuildSettings = @{ @"Shared": @"", @"Release": @"", @"Debug": @"" };
+    XCTAssertFalse(dictionaryWithoutBuildSettings.containsBuildSettings);
+    
+    NSDictionary *badDictionary = @{@"Shared":@"", @"Release":@"", @"Debug":[NSDate date] };
+    BOOL result = NO;
+    XCTAssertThrows(result = badDictionary.containsBuildSettings);
+}
+
 @end