Add --fail-fast CLI option to the runner::Basic

CHANGELOG.md

@@ -11,11 +11,16 @@ All user visible changes to `cucumber` crate will be documented in this file. Th
 
 [Diff](/../../compare/v0.11.0...v0.11.1) | [Milestone](/../../milestone/6)
 
+### Added
+
+- `--fail-fast` CLI option to `runner::Basic`. ([#196])
+
 ### Changed
 
 - Optimized `runner::Basic` to not wait the whole batch to complete before executing next `Scenario`s. ([#195])
 
 [#195]: /../../pull/195
+[#196]: /../../pull/196
 
 
 

book/src/cli.md

@@ -25,6 +25,9 @@ OPTIONS:
             Coloring policy for a console output
 
             [default: auto]
+
+        --fail-fast
+            Run tests until the first failure
 
     -h, --help
             Print help information

book/src/quickstart.md

@@ -274,6 +274,8 @@ fn cat_is_fed(world: &mut AnimalWorld) {
 And see the test failing:  
 ![record](rec/quickstart_simple_fail.gif)
 
+> __TIP__: By default, unlike [unit tests](https://doc.rust-lang.org/cargo/commands/cargo-test.html#test-options), failed [step]s don't terminate the execution instantly, and the whole test suite is executed regardless of them. Use `--fail-fast` [CLI] option to stop execution on first failure.
+
 What if we also want to validate that even if the cat was never hungry to begin with, it won't end up hungry after it was fed? So, we may add an another [scenario] that looks quite similar:
 ```gherkin
 Feature: Animal feature

book/src/writing/asserting.md

@@ -76,6 +76,8 @@ fn cat_is_fed(_: &mut AnimalWorld) {
 
 > __TIP__: To additionally print the state of the `World` at the moment of failure, increase output verbosity via `-vv` [CLI] option.
 
+> __TIP__: By default, unlike [unit tests](https://doc.rust-lang.org/cargo/commands/cargo-test.html#test-options), failed [step]s don't terminate the execution instantly, and the whole test suite is executed regardless of them. Use `--fail-fast` [CLI] option to stop execution on first failure.
+