iOS - 'MyProject-Swift.h' file not found when running Unit Tests for Swift

Question

I am trying to setup Unit Testing for my project. It is an existing Objective-C app, that I have recently added one Swift class to. I have setup the 'MyProject-Swift.h' and Swift Bridging files (both 'MyProject' and 'MyProjectTest') and I am able to build and run the app just fine using both Objective-C and Swift code.

However, now I want to run some Unit Tests on the new Swift class. I setup my test file and it looks like the following:

MySwiftClassTests.swift:

import UIKit
import XCTest
import MyProject

class MySwiftClassTests: XCTestCase {

    override func setUp() {
        super.setUp()
        // Put setup code here. This method is called before the invocation of each test method in the class.
    }

    override func tearDown() {
        // Put teardown code here. This method is called after the invocation of each test method in the class.
        super.tearDown()
    }

    func testExample() {
        // This is an example of a functional test case.
        XCTAssert(true, "Pass")
    }

    func testPerformanceExample() {
        // This is an example of a performance test case.
        self.measureBlock() {
            // Put the code you want to measure the time of here.
        }
    }

}

I get this error when running the app as Test:

'MyProject-Swift.h' file not found

I am not sure why this happens only when trying to run the Tests. Any suggestions?

Answer 1

"MyProject-Swift.h" file is generated at following path:

"$(TARGET_TEMP_DIR)/../$(PROJECT_NAME).build/DerivedSources"

I end up adding this to Header Search Paths for my Unit Test target.

Also as @hyouuu pointed out about being the known issue, hopefully Apple will provide some good solution at their end. Until I believe we need to use this above solution.

https://developer.apple.com/library/content/documentation/Xcode/Conceptual/RN-Xcode-Archive/Chapters/xc6_release_notes.html

Answer 2

Thanks to @gagarwal for figuring this out. In our case the product name has a space, which is collapsed in $PROJECT_NAME, so I had to hard code it. Additionally, by using $CONFIGURATION_TEMP_DIR instead of $TARGET_TEMP_DIR, you can remove the parent directory (../) from the path. So the solution is to add the following to the Header Search Paths in your test target:

"$(CONFIGURATION_TEMP_DIR)/Product Name With Spaces.build/DerivedSources"

Or, if your product does not contain spaces:

"$(CONFIGURATION_TEMP_DIR)/$(PROJECT_NAME).build/DerivedSources"

Answer 3

Saw in the Xcode 6.1 release note, that this is a known issue... sign... Search for "-swift.h" in the release note https://developer.apple.com/library/content/documentation/Xcode/Conceptual/RN-Xcode-Archive/Chapters/xc6_release_notes.html

Tests written in Objective-C cannot import the Swift generated interfaces header ($(PRODUCT_MODULE_NAME)-Swift.h) for application targets, and therefore cannot be used to test code that requires this header.

Tests for Swift code should be written in Swift. Tests written in Objective-C for framework targets can access the Swift generated interfaces by importing the framework module using @import FrameworkName;. (16931027)

Please see @gagarwal's workaround below which WORKS!

Answer 4

I had a similar issue to yours, I think; here was my setup.

I had an object defined in Swift:

// file Foo.swift
@objc public class Foo {
    // ...
}

This class was then used in the initializer of an Objective-C object:

// file Bar.h
#import "MyProject-Swift.h"

@interface Bar: NSObject

- (instancetype)initWithFoo:(Foo *)foo;

@end

This made my unit tests for Bar not compile, since the MyProject-Swift.h header isn't real and the unit test target can't see it. The release note shared by @hyouuu is on point - but I'm not testing a Swift class, I'm testing an Objective-C class!

I was able to fix this by changing the header file for Bar to use a forward class reference instead:

// file Bar.h
@class Foo;

@interface Bar: NSObject

- (instancetype)initWithFoo:(Foo *)foo;

@end

I then included MyProject-Swift.h in Bar.m, and everything worked - my tests of Objective-C objects written in Objective-C compiled properly and continued running, and I could write new tests for Swift objects in Swift.

Hope this helps!

Answer 5

After I tried out everything I could find on the topic, the thing that worked for me was actually running the app although it was still showing the 'ModuleName-Swift.h file not found' error.

It went away and my app works perfectly fine. I guess I should have considered that earlier... The error keeps coming back, but after running the app it always just goes away again. So the issue is not really solved for me, but I can continue working on other topics for now...

Answer 6

A simple

@testable import MyProject

has done the job for me.