Hard wrap tutorial doc for easier raw Markdown reading

Hard wrap text on tutorial doc to 72 column limit, to make it easier to
be read the raw Mardown from text editor.

Also, make consistent the usage of two spaces after period.

Author: David Álvarez Rosa

docs/tutorial.md

@@ -12,16 +12,20 @@
 
 ## Getting Catch2
 
-Ideally you should be using Catch2 through its [CMake integration](cmake-integration.md#top).
-Catch2 also provides pkg-config files and two file (header + cpp)
-distribution, but this documentation will assume you are using CMake. If
-you are using the two file distribution instead, remember to replace
-the included header with `catch_amalgamated.hpp`.
+Ideally you should be using Catch2 through its [CMake
+integration](cmake-integration.md#top).  Catch2 also provides pkg-config
+files and two file (header + cpp) distribution, but this documentation
+will assume you are using CMake.  If you are using the two file
+distribution instead, remember to replace the included header with
+`catch_amalgamated.hpp`.
 
 
 ## Writing tests
 
-Let's start with a really simple example ([code](../examples/010-TestCase.cpp)). Say you have written a function to calculate factorials and now you want to test it (let's leave aside TDD for now).
+Let's start with a really simple example
+([code](../examples/010-TestCase.cpp)).  Say you have written a function
+to calculate factorials and now you want to test it (let's leave aside
+TDD for now).
 
 ```c++
 unsigned int Factorial( unsigned int number ) {
@@ -44,7 +48,12 @@ TEST_CASE( "Factorials are computed", "[factorial]" ) {
 }
 ```
 
-This will compile to a complete executable which responds to [command line arguments](command-line.md#top). If you just run it with no arguments it will execute all test cases (in this case there is just one), report any failures, report a summary of how many tests passed and failed and return the number of failed tests (useful for if you just want a yes/ no answer to: "did it work").
+This will compile to a complete executable which responds to [command
+line arguments](command-line.md#top).  If you just run it with no
+arguments it will execute all test cases (in this case there is just
+one), report any failures, report a summary of how many tests passed and
+failed and return the number of failed tests (useful for if you just
+want a yes/ no answer to: "did it work").
 
 Anyway, as the tests above as written will pass, but there is a bug.
 The problem is that `Factorial(0)` should return 1 (due to [its
@@ -61,8 +70,8 @@ TEST_CASE( "Factorials are computed", "[factorial]" ) {
 }
 ```
 
-After another compile & run cycle, we will see a test failure. The output
-will look something like:
+After another compile & run cycle, we will see a test failure. The
+output will look something like:
 
 ```
 Example.cpp:9: FAILED:
@@ -71,11 +80,12 @@ with expansion:
   0 == 1
 ```
 
-Note that the output contains both the original expression,
-`REQUIRE( Factorial(0) == 1 )` and the actual value returned by the call
-to the `Factorial` function: `0`.
+Note that the output contains both the original expression, `REQUIRE(
+Factorial(0) == 1 )` and the actual value returned by the call to the
+`Factorial` function: `0`.
 
 We can fix this bug by slightly modifying the `Factorial` function to:
+
 ```c++
 unsigned int Factorial( unsigned int number ) {
   return number > 1 ? Factorial(number-1)*number : 1;
@@ -86,36 +96,38 @@ unsigned int Factorial( unsigned int number ) {
 ### What did we do here?
 
 Although this was a simple test it's been enough to demonstrate a few
-things about how Catch2 is used. Let's take a moment to consider those
+things about how Catch2 is used.  Let's take a moment to consider those
 before we move on.
 
-* We introduce test cases with the `TEST_CASE` macro. This macro takes
+* We introduce test cases with the `TEST_CASE` macro.  This macro takes
   one or two string arguments - a free form test name and, optionally,
-  one or more tags (for more see [Test cases and Sections](#test-cases-and-sections)).
+  one or more tags (for more see [Test cases and
+  Sections](#test-cases-and-sections)).
 * The test automatically self-registers with the test runner, and user
-  does not have do anything more to ensure that it is picked up by the test
-  framework. _Note that you can run specific test, or set of tests,
-  through the [command line](command-line.md#top)._
+  does not have do anything more to ensure that it is picked up by the
+  test framework.  _Note that you can run specific test, or set of
+  tests, through the [command line](command-line.md#top)._
 * The individual test assertions are written using the `REQUIRE` macro.
   It accepts a boolean expression, and uses expression templates to
-  internally decompose it, so that it can be individually stringified
-  on test failure.
+  internally decompose it, so that it can be individually stringified on
+  test failure.
 
 On the last point, note that there are more testing macros available,
 because not all useful checks can be expressed as a simple boolean
-expression. As an example, checking that an expression throws an exception
-is done with the `REQUIRE_THROWS` macro. More on that later.
+expression.  As an example, checking that an expression throws an
+exception is done with the `REQUIRE_THROWS` macro.  More on that later.
 
 
 ## Test cases and sections
 
-Like most test frameworks, Catch2 supports a class-based fixture mechanism,
-where individual tests are methods on class and setup/teardown can be
-done in constructor/destructor of the type.
+Like most test frameworks, Catch2 supports a class-based fixture
+mechanism, where individual tests are methods on class and
+setup/teardown can be done in constructor/destructor of the type.
 
 However, their use in Catch2 is rare, because idiomatic Catch2 tests
-instead use _sections_ to share setup and teardown code between test code.
-This is best explained through an example ([code](../examples/100-Fix-Section.cpp)):
+instead use _sections_ to share setup and teardown code between test
+code.  This is best explained through an example
+([code](../examples/100-Fix-Section.cpp)):
 
 ```c++
 TEST_CASE( "vectors can be sized and resized", "[vector]" ) {
@@ -152,17 +164,18 @@ TEST_CASE( "vectors can be sized and resized", "[vector]" ) {
 }
 ```
 
-For each `SECTION` the `TEST_CASE` is executed from the start. This means
-that each section is entered with a freshly constructed vector `v`, that
-we know has size 5 and capacity at least 5, because the two assertions
-are also checked before the section is entered. Each run through a test
-case will execute one, and only one, leaf section.
+For each `SECTION` the `TEST_CASE` is executed from the start.  This
+means that each section is entered with a freshly constructed vector
+`v`, that we know has size 5 and capacity at least 5, because the two
+assertions are also checked before the section is entered.  Each run
+through a test case will execute one, and only one, leaf section.
 
 Section can also be nested, in which case the parent section can be
-entered multiple times, once for each leaf section. Nested sections are
+entered multiple times, once for each leaf section.  Nested sections are
 most useful when you have multiple tests that share part of the set up.
 To continue on the vector example above, you could add a check that
-`std::vector::reserve` does not remove unused excess capacity, like this:
+`std::vector::reserve` does not remove unused excess capacity, like
+this:
 
 ```cpp
     SECTION( "reserving bigger changes capacity but not size" ) {
@@ -179,47 +192,50 @@ To continue on the vector example above, you could add a check that
 ```
 
 Another way to look at sections is that they are a way to define a tree
-of paths through the test. Each section represents a node, and the final
-tree is walked in depth-first manner, with each path only visiting only
-one leaf node.
+of paths through the test.  Each section represents a node, and the
+final tree is walked in depth-first manner, with each path only visiting
+only one leaf node.
 
-There is no practical limit on nesting sections, as long as your compiler
-can handle them, but keep in mind that overly nested sections can become
-unreadable. From experience, having section nest more than 3 levels is
-usually very hard to follow and not worth the removed duplication.
+There is no practical limit on nesting sections, as long as your
+compiler can handle them, but keep in mind that overly nested sections
+can become unreadable.  From experience, having section nest more than 3
+levels is usually very hard to follow and not worth the removed
+duplication.
 
 
 ## BDD style testing
 
-Catch2 also provides some basic support for BDD-style testing. There are
-macro aliases for `TEST_CASE` and `SECTIONS` that you can use so that
-the resulting tests read as BDD spec. `SCENARIO` acts as a `TEST_CASE`
-with "Scenario: " name prefix. Then there are `GIVEN`, `WHEN`, `THEN`
-(and their variants with `AND_` prefix), which act as a `SECTION`,
-similarly prefixed with the macro name.
+Catch2 also provides some basic support for BDD-style testing.  There
+are macro aliases for `TEST_CASE` and `SECTIONS` that you can use so
+that the resulting tests read as BDD spec. `SCENARIO` acts as a
+`TEST_CASE` with "Scenario: " name prefix. Then there are `GIVEN`,
+`WHEN`, `THEN` (and their variants with `AND_` prefix), which act as a
+`SECTION`, similarly prefixed with the macro name.
 
 For more details on the macros look at the [test cases and
-sections](test-cases-and-sections.md#top) part of the reference docs,
-or at the [vector example done with BDD macros](../examples/120-Bdd-ScenarioGivenWhenThen.cpp).
+sections](test-cases-and-sections.md#top) part of the reference docs, or
+at the [vector example done with BDD
+macros](../examples/120-Bdd-ScenarioGivenWhenThen.cpp).
 
 
 ## Data and Type driven tests
 
-Test cases in Catch2 can also be driven by types, input data, or both
-at the same time.
+Test cases in Catch2 can also be driven by types, input data, or both at
+the same time.
 
-For more details look into the Catch2 reference, either at the
-[type parametrized test cases](test-cases-and-sections.md#type-parametrised-test-cases),
-or [data generators](generators.md#top).
+For more details look into the Catch2 reference, either at the [type
+parametrized test
+cases](test-cases-and-sections.md#type-parametrised-test-cases), or
+[data generators](generators.md#top).
 
 
 ## Next steps
 
 This page is a brief introduction to get you up and running with Catch2,
-and to show the basic features of Catch2. The features mentioned here
-can get you quite far, but there are many more. However, you can read
-about these as you go, in the ever-growing [reference section](Readme.md#top)
-of the documentation.
+and to show the basic features of Catch2.  The features mentioned here
+can get you quite far, but there are many more.  However, you can read
+about these as you go, in the ever-growing [reference
+section](Readme.md#top) of the documentation.
 
 
 ---