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| 1 | +Architecture and Hacking the tmc-cli |
| 2 | +==================================== |
| 3 | + |
| 4 | +## Requirements for developing tmc-cli |
| 5 | + * jdk 7 |
| 6 | + * linux bash (mac's bash won't work) |
| 7 | + |
| 8 | + |
| 9 | +## Building tmc-cli |
| 10 | +To build tmc-cli run the appropriate Maven command. |
| 11 | + |
| 12 | + $ git clone https://github.com/tmc-cli/tmc-cli.git |
| 13 | + $ mvn clean install |
| 14 | + |
| 15 | +## Architecture |
| 16 | + |
| 17 | +Program architecture is based on command design pattern. The program runs only a single command |
| 18 | +on each program execution. |
| 19 | + |
| 20 | +Conceptually, there are three main parts in the program; the launch code, backend related code |
| 21 | +and the commands. The commands are gathered into their own package. In addition, there are utility |
| 22 | +classes in order to take care of user input/output and file handling. |
| 23 | + |
| 24 | +The tmc-cli itself is mostly just an command line interface for the backend libraries. |
| 25 | +All the heavy lifting is done by [tmc-core](https://github.com/testmycode/tmc-core) and |
| 26 | +[tmc-langs](https://github.com/testmycode/tmc-langs) libraries. The tmc-cli also requires the |
| 27 | +server-side component of TestMyCode aka. [tmc-server](https://github.com/testmycode/tmc-server). |
| 28 | + |
| 29 | +### Important classes |
| 30 | + |
| 31 | +The `CliContext` object contains some cached data and singleton objects that are commonly used |
| 32 | +by utility classes and commands. Most importantly it has the `Io` object which is responsible |
| 33 | +for printing messages for the user and helping with other user interactions. |
| 34 | + |
| 35 | +The `WorkDir` object handles most of the directory path handling. And it's used by most |
| 36 | +commands to parse the exercise arguments. |
| 37 | + |
| 38 | +The `TmcUtil` class has wraps all tmc-cores functions into nicer interfac. |
| 39 | + |
| 40 | +## Creating new commands |
| 41 | + |
| 42 | +Every command must have `@Command` annotation and it's highly recommended to extend the |
| 43 | +AbstractCommand class. Note that the `@Command` annotation is used for creating help messages |
| 44 | +and its 'name' field is used as the sub-command name in terminal. |
| 45 | + |
| 46 | +Please create all new commands inside the `command` package. |
| 47 | + |
| 48 | +```java |
| 49 | +@Command(name = "command-name", desc = "Command description goes here") |
| 50 | +public class ExampleCommand extends AbstractCommand { |
| 51 | + @Override |
| 52 | + public void getOptions(Options options) { |
| 53 | + options.addOption("l", "long-option", false, "This will be seen in the help message."); |
| 54 | + // ... |
| 55 | + } |
| 56 | +} |
| 57 | +``` |
| 58 | + |
| 59 | +## Logging error messages |
| 60 | + |
| 61 | +In case of failure, please print debug info in the error log by using slf4j logger and print some |
| 62 | +useful error messages to user with `ctx.getIo().println(' ... ');`. Ctx context object is |
| 63 | +passed into most of the code in tmc-cli and you can use it to interact with the user. |
| 64 | + |
| 65 | +## Unit testing |
| 66 | + |
| 67 | +If you create a new command, please use integration tests only. If you want to verify that a command |
| 68 | +or a utility class has printed text into the terminal, use `io.assertContains()` method. This custom |
| 69 | +assert method prints easily understandable error messages when it fails and doesn't require much code. |
| 70 | + |
| 71 | +```java |
| 72 | +@RunWith(PowerMockRunner.class) |
| 73 | +@PrepareForTest(TmcUtil.class) |
| 74 | +public class ExampleCommandTest { |
| 75 | + |
| 76 | + private Application app; |
| 77 | + private CliContext ctx; |
| 78 | + private TestIo io; |
| 79 | + private TmcCore mockCore; |
| 80 | + private WorkDir workDir; |
| 81 | + private Path tempDir; |
| 82 | + |
| 83 | + @Before |
| 84 | + public void setUp() { |
| 85 | + // redirect the course related files into tmp |
| 86 | + tempDir = Paths.get(System.getProperty("java.io.tmpdir")).resolve("exampleTest"); |
| 87 | + workDir = new WorkDir(tempDir); |
| 88 | + |
| 89 | + io = new TestIo(); |
| 90 | + mockCore = mock(TmcCore.class);// make sure that nothing is leaked to tmcCore |
| 91 | + ctx = new CliContext(io, workDir, mockCore); |
| 92 | + app = new Application(ctx); |
| 93 | + |
| 94 | + mockStatic(TmcUtil.class); |
| 95 | + } |
| 96 | + |
| 97 | + @After |
| 98 | + public void tearDown() { |
| 99 | + try { |
| 100 | + FileUtils.deleteDirectory(tempDir.toFile()); |
| 101 | + } catch (Exception e) { } |
| 102 | + } |
| 103 | + |
| 104 | + @Test |
| 105 | + public void exampleSucceedsWhenGivenValidCourse() { |
| 106 | + course = ...; |
| 107 | + when(TmcUtil.findCourse(eq(ctx), eq("course1"))).thenReturn(course); |
| 108 | + |
| 109 | + String[] args = {"example course1"}; |
| 110 | + app.run(args); |
| 111 | + io.assertContains("something went right"); |
| 112 | + } |
| 113 | +} |
| 114 | +``` |
| 115 | + |
| 116 | +If you are doing tests for any other class, simply create normal unit tests |
| 117 | +that don't depend on any command. |
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