Power assertions (a.k.a. diagrammed assertions) augment your assertion failures with information about values produced during the evaluation of a condition, and presents them in an easily digestible form. Power assertions are a popular feature of Spock (and later the whole Groovy language independently of Spock), ScalaTest, and Expecty.
Power assertions provide descriptive assertion messages for your tests, like this.
XCTAssert(max(a, b) == c)
| | | | |
7 4 7 | 12
false
XCTAssert(xs.contains(4))
| | |
| false 4
[1, 2, 3]
XCTAssert("hello".hasPrefix("h") && "goodbye".hasSuffix("y"))
| | | | | | |
"hello" true "h" | "goodbye" false "y"
false
Live demo for SwiftPowerAssert
https://swift-power-assert.kishikawakatsumi.com/
git clone https://github.com/kishikawakatsumi/SwiftPowerAssert
cd SwiftPowerAssert
swift build -c releaseCopy the file (.build/release/swift-power-assert) to your binary location.
Replace xcodebuild test... command with swift-power-assert xctest -Xxcodebuild test ...
/path/to/swift-power-assert xctest -Xxcodebuild test -scheme Atlas-PackageReplace swift test... command with swift-power-assert test -Xswift test ...
/path/to/swift-power-assert test -Xswift testNote: SwiftPowerAssert injects instrument code into the family of XCTAssert() methods during tests. SwiftPowerAssert back up the source files before executing tests and restore automatically when the tests finished. However, the original files may not be restored due to an unexpected crash or something wrong. Please use it for the project under Git.
You can run the sample project with the following command:
swift build -c release
(cd Fixtures/Atlas && ../../.build/release/swift-power-assert test -Xswift test)
USAGE: swift-power-assert [options] subcommand [options]
OPTIONS:
--verbose Show more debugging information
--help Display available options
SUBCOMMANDS:
test Run swift test with power assertion
xctest Run XCTest with power assertion.
You can pass any xcodebuild or swift options after -Xxcodebuild or -Xswift.
/path/to/swift-power-assert xctest -Xxcodebuild test -project Atlas.xcodeproj -scheme Atlas-Package \
-sdk iphonesimulator -destination "name=iPhone X,OS=11.2"/path/to/swift-power-assert test -Xswift test -c release -Xswiftc -enable-testingNothing happens? If the test succeeds, nothing is output. If you always want to see rich ASCII art, enable the --verbose option. always output a diagram regardless of the success or failure of assertions.
/path/to/swift-power-assert --verbose xctest -Xxcodebuild test -project Atlas.xcodeproj -scheme Atlas-Package/path/to/swift-power-assert --verbose test -Xswift testlet a = 10
let b = 9
XCTAssert(a * b == 91)
// Output:
// XCTAssert(a * b == 91)
// | | | | |
// | | 9 | 91
// | 90 false
// 10let xs = [1, 2, 3]
XCTAssert(xs.contains(4))
// Output:
// XCTAssert(xs.contains(4))
// | | |
// | false 4
// [1, 2, 3]XCTAssert("hello".hasPrefix("h") && "goodbye".hasSuffix("y"))
// Output:
// XCTAssert("hello".hasPrefix("h") && "goodbye".hasSuffix("y"))
// | | | | | | |
// "hello" true "h" | "goodbye" false "y"
// falselet d = 4
let e = 7
let f = 12
XCTAssert(max(d, e) == f)
XCTAssert(d + e > f)
// Output:
// XCTAssert(max(d, e) == f)
// | | | | |
// 7 4 7 | 12
// false
// XCTAssert(d + e > f)
// | | | | |
// 4 | 7 | 12
// 11 falsestruct Person {
let name: String
let age: Int
var isTeenager: Bool {
return age <= 12 && age >= 20
}
}
let john = Person(name: "John", age: 42)
let mike = Person(name: "Mike", age: 13)
XCTAssert(john.isTeenager)
XCTAssert(mike.isTeenager && john.age < mike.age)
// Output:
// XCTAssert(john.isTeenager)
// | |
// | false
// Person(name: "John", age: 42)
// XCTAssert(mike.isTeenager && john.age < mike.age)
// | | | | | | | |
// | false | | 42 | | 13
// | | | | Person(name: "Mike", age: 13)
// | | | false
// | | Person(name: "John", age: 42)
// | false
// Person(name: "Mike", age: 13)Kishikawa Katsumi, kishikawakatsumi@mac.com
SwiftPowerAssert is available under the Apache 2.0 license. See the LICENSE file for more info.