Initial Commit

rust/hello-world/Cargo.lock

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+[root]
+name = "hello-world"
+version = "0.0.0"
+

rust/hello-world/Cargo.toml

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+[package]
+name = "hello-world"
+version = "0.0.0"

rust/hello-world/GETTING_STARTED.md

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+# Getting Started
+
+These exercises lean on Test-Driven Development (TDD), but they're not
+an exact match.
+
+The following steps assume that you are in the same directory as the exercise.
+
+You must have rust installed.
+Follow the [Installing Rust chapter in the Rust book](http://doc.rust-lang.org/stable/book/installing-rust.html).
+The [getting started with rust](http://help.exercism.io/getting-started-with-rust.html)
+section from exercism is also useful.
+
+## Step 1
+
+Run the test suite. It can be run with `cargo`, which is installed with rust.
+
+```
+$ cargo test
+```
+
+This will fail, complaining that `hello-world` could not compile.
+
+To fix this, create a new directory called `src`.
+Create a new file called, `lib.rs`, inside the `src` directory.
+
+## Step 2
+
+Run the test again. It will give you a new error, another compile error.
+Our `lib.rs` does not contain any code, specifically the `hello()`
+function that our test is looking for.
+
+### Fixing the Error
+
+To fix it, open up the `src/lib.rs` file and add the following code:
+
+```rust
+pub fn hello(name: Option<&str>) -> String {
+    "".to_string()
+}
+```
+
+Our test is looking for the `hello()` function from the `hello_world`
+crate. `lib.rs`, by default, is our crate root and our test
+is looking for the `hello()` function there.
+
+The code we are adding to `lib.rs` defines a public function (`pub fn`) that is called "hello".
+The function accepts a `name` as an optional argument (`Option`).
+The function returns a `String`.
+We start by returning an empty string (`"".to_string()`).
+
+## Step 3
+
+Run the test again.
+
+This time, code compilation will pass and we receive actual test failures.
+
+```
+running 3 tests
+test test_other_same_name ... ignored
+test test_sample_name ... ignored
+test test_no_name ... FAILED
+
+failures:
+
+---- test_no_name stdout ----
+thread 'test_no_name' panicked at 'assertion failed: `(left == right)`
+(left: `"Hello, World!"`, right: `""`)', tests/hello-world.rs:5
+
+
+failures:
+    test_no_name
+
+test result: FAILED. 0 passed; 1 failed; 2 ignored; 0 measured
+```
+
+### Understanding Test Failures
+
+Only one of the tests runs (`test_no_name`) and it fails. The other
+tests are ignored (more on that later).
+
+The `test_no_name` failure states that it is expecting the value,
+`"Hello, World!"`, to be returned from `hello("")`.
+The left side of the assertion (at line 5) should be equal to the right side.
+
+```
+---- test_no_name stdout ----
+thread 'test_no_name' panicked at 'assertion failed: `(left == right)`
+(left: `"Hello, World!"`, right: `""`)', tests/hello-world.rs:5
+```
+
+To fix it, let's return `"Hello, World!"`, instead of an empty string
+(`""`) inside our `hello` function.
+
+```rust
+pub fn hello(name: Option<&str>) -> String {
+    "Hello, World!".to_string()
+}
+```
+
+## Step 4
+
+Run the test again. This time, it will pass.
+
+```
+running 3 tests
+test test_other_same_name ... ignored
+test test_sample_name ... ignored
+test test_no_name ... ok
+
+test result: ok. 1 passed; 0 failed; 2 ignored; 0 measured
+
+   Doc-tests hello-world
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured
+```
+
+You may have noticed compiler warnings earlier:
+
+```
+Compiling hello-world v0.0.0
+(file:////exercism/exercises/rust/hello-world)
+src/lib.rs:1:14: 1:18 warning: unused variable: `name`, #[warn(unused_variables)] on by default
+src/lib.rs:1 pub fn hello(name: Option<&str>) -> String {
+                          ^~~~
+```
+
+Our `hello` function does not use the `name` argument so the
+compiler is letting us know that we could potentially remove the
+argument from our function (it likes "clean code").
+
+As we make the rest of the tests pass, we will find that we need the `name`
+argument, so don't delete it.
+
+Activate the next test. Open the `tests/hello-world.rs` file.
+Delete the `#[ignore]` line for the `test_sample_name` test.
+
+## Step 5
+
+Run the test suite again. Read the test failure and make the test pass.
+
+As a reminder, the [rust book](http://doc.rust-lang.org/stable/book/README.html)
+is a good reference for understanding rust.
+The cargo output may also have hints to help you, depending on the errors you get.
+For example, `rustc --explain E0425` will explain unresolved name errors.
+
+## Wash, Rinse, Repeat
+
+Delete one `#[ignore]`  at a time, and make each test pass before you move to
+the next one.
+
+## Submit
+
+When everything is passing, you can submit your code with the following
+command:
+
+```
+$ exercism submit src/lib.rs
+```

rust/hello-world/README.md

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+# Hello World
+
+Write a program that greets the user by name, or by saying "Hello, World!" if no name is given.
+
+["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is the traditional first program for beginning programming in a new language.
+
+**Note:** You can skip this exercise by running:
+
+    exercism skip $LANGUAGE hello-world
+
+## Specification
+
+The `Hello World!` program will greet me, the caller.
+
+If I tell the program my name is Alice, it will greet me by saying "Hello, Alice!".
+
+If I neglect to give it my name, it will greet me by saying "Hello, World!"
+
+## Test-Driven Development
+
+As programmers mature, they eventually want to test their code.
+
+Here at Exercism we simulate [Test-Driven Development](http://en.wikipedia.org/wiki/Test-driven_development) (TDD), where you write your tests before writing any functionality. The simulation comes in the form of a pre-written test suite, which will signal that you have solved the problem.
+
+It will also provide you with a safety net to explore other solutions without breaking the functionality.
+
+### A typical TDD workflow on Exercism:
+
+1. Run the test file and pick one test that's failing.
+2. Write some code to fix the test you picked.
+3. Re-run the tests to confirm the test is now passing.
+4. Repeat from step 1.
+5. [Submit your solution](http://help.exercism.io/submitting-exercises.html).
+
+## Instructions
+
+Submissions are encouraged to be general, within reason. Having said that, it's also important not to over-engineer a solution.
+
+It's important to remember that the goal is to make code as expressive and readable as we can. However, solutions to the hello-world exercise will be not be reviewed by a person, but by rikki- the robot, who will offer an encouraging word.
+
+## Rust Installation
+
+Refer to the [exercism help page][help-page] for Rust installation and learning
+resources.
+
+## Writing the Code
+
+Execute the tests with:
+
+```bash
+$ cargo test
+```
+
+All but the first test have been ignored.  After you get the first test to
+pass, remove the ignore flag (`#[ignore]`) from the next test and get the tests
+to pass again.  The test file is located in the `tests` directory.   You can
+also remove the ignore flag from all the tests to get them to run all at once
+if you wish.
+
+Make sure to read the [Crates and Modules](crates-and-modules) chapter if you
+haven't already, it will help you with organizing your files.
+
+[help-page]: http://help.exercism.io/getting-started-with-rust.html
+[crates-and-modules]: http://doc.rust-lang.org/stable/book/crates-and-modules.html
+
+## Source
+
+This is a program to introduce users to using Exercism [view source](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program)

rust/hello-world/tests/hello-world.rs

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+extern crate hello_world;
+
+#[test]
+fn test_no_name() {
+    assert_eq!("Hello, World!", hello_world::hello(None));
+}
+
+#[test]
+#[ignore]
+fn test_sample_name() {
+    assert_eq!("Hello, Alice!", hello_world::hello(Some("Alice")));
+}
+
+#[test]
+#[ignore]
+fn test_other_same_name() {
+    assert_eq!("Hello, Bob!", hello_world::hello(Some("Bob")));
+}