From 323ca5cd43e491232f163c024b013a063f277455 Mon Sep 17 00:00:00 2001
From: John Bampton <jbampton@gmail.com>
Date: Sat, 13 Feb 2021 19:36:34 +1000
Subject: [PATCH] feat: add a GitHub Action to check for trailing whitespace in
 all files

---
 .github/workflows/lint.yml             |  9 ++++
 doc/index.md                           |  2 +-
 doc/library/math.md                    | 58 +++++++++++++-------------
 utils/check-for-trailing-whitespace.sh | 13 ++++++
 4 files changed, 52 insertions(+), 30 deletions(-)
 create mode 100755 utils/check-for-trailing-whitespace.sh

diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index dc75fbd..69963cc 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -21,6 +21,15 @@ jobs:
       - uses: actions/checkout@v2
       - name: 🧹 ShellCheck
         uses: ludeeus/action-shellcheck@master
+  trailing-whitespace:
+    name: 🧋 Trailing whitespace
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: 🧹 Check for trailing whitespace
+        run: |
+          cd utils || exit
+          sh ./check-for-trailing-whitespace.sh || exit 1
   yamllint:
     name: 🍺 YAML
     runs-on: ubuntu-latest
diff --git a/doc/index.md b/doc/index.md
index 5b5de3d..e4e4ca8 100644
--- a/doc/index.md
+++ b/doc/index.md
@@ -1,3 +1,3 @@
 ## Library
 
-[math](https://github.com/matz/streem/doc/library/math.md)  
+[math](https://github.com/matz/streem/doc/library/math.md)
diff --git a/doc/library/math.md b/doc/library/math.md
index 04fc091..9dfad98 100644
--- a/doc/library/math.md
+++ b/doc/library/math.md
@@ -1,6 +1,6 @@
 # Math
 
-Streem has a lot Mathematical functions defined by the C standard.  
+Streem has a lot Mathematical functions defined by the C standard.
 
 ## Constants
 
@@ -15,7 +15,7 @@ print(PI)
 
 ### E
 
-The mathematical constant e = 2.718281…, to available precision.  
+The mathematical constant e = 2.718281…, to available precision.
 
 ```
 # Output: 2.718281828459
@@ -26,7 +26,7 @@ print(E)
 
 ### ceil(x)
 
-Return the ceiling of x.  
+Return the ceiling of x.
 
 ```
 # Output: 46
@@ -35,7 +35,7 @@ print(ceil(45.54))
 
 ### fabs(x)
 
-Return the absolute value of x.  
+Return the absolute value of x.
 
 ```
 # Output: 2
@@ -53,20 +53,20 @@ print(gcd(4,10))
 
 ### trunc(x)
 
-Return the Real value x truncated to an Integral.  
+Return the Real value x truncated to an Integral.
 
 ```
 Output: 9
 print(trunc(9.13))
-```  
+```
 
 ### int(x)
 
-Same as trunc(x).  
+Same as trunc(x).
 
 ### floor(x)
 
-Return the floor of x.  
+Return the floor of x.
 
 ```
 # Output: 2
@@ -75,7 +75,7 @@ print(floor(2.7))
 
 ### round(x)
 
-Return the rounding of x.  
+Return the rounding of x.
 
 ```
 # Output: 10
@@ -104,80 +104,80 @@ print(ldexp(6,3))
 
 ### sin(x)
 
-Return the sine of x.  
+Return the sine of x.
 
 ### cos(x)
 
-Return the cosine of x.  
+Return the cosine of x.
 
 ### tan(x)
 
-Return the tangent of x.  
+Return the tangent of x.
 
 ### asin(x)
 
-Return the arc sine of x.  
+Return the arc sine of x.
 
 ### acos(x)
 
-Return the arc cosine of x.  
+Return the arc cosine of x.
 
 ### atan(x)
 
-Return the arc tangent of x.  
+Return the arc tangent of x.
 
 ### hypot(x, y)
 
-Return the `sqrt(x * x + y * y)`(Euclidean norm).  
+Return the `sqrt(x * x + y * y)`(Euclidean norm).
 
 ```
 # Output: 5
 print(hypot(3,4))
-```  
+```
 
 ## Hyperbolic functions
 
 ### asinh(x)
 
-Return the inverse hyperbolic sine of x.  
+Return the inverse hyperbolic sine of x.
 
 ### acosh(x)
 
-Return the inverse hyperbolic cosine of x.  
+Return the inverse hyperbolic cosine of x.
 
 ### atanh(x)
 
-Return the inverse hyperbolic tangent of x.  
+Return the inverse hyperbolic tangent of x.
 
 ### cosh(x)
 
-Return the hyperbolic cosine of x.  
+Return the hyperbolic cosine of x.
 
 ### sinh(x)
 
-Return the hyperbolic sine of x.  
+Return the hyperbolic sine of x.
 
 ### tanh(x)
 
-Return the hyperbolic tangent of x.  
+Return the hyperbolic tangent of x.
 
 ## logarithmic functions
 
 ### exp(x)
 
-Return e raised to the power x.  
+Return e raised to the power x.
 
 ### log(x)
 
-Return the natural logarithm of x.  
+Return the natural logarithm of x.
 
 ### log2(x)
 
-Return the base-2 logarithm of x.  
+Return the base-2 logarithm of x.
 
 ### log10(x)
 
-Return the base-10 logarithm of x.  
+Return the base-10 logarithm of x.
 
 ## Power functions
 
@@ -188,7 +188,7 @@ Return x raised to the power y.
 ```
 # Output: 25
 print(pow(5,2))
-```  
+```
 
 ### sqrt(x)
 
@@ -197,4 +197,4 @@ Return the square root of x.
 ```
 # Output: 5
 print(sqrt(25))
-```  
+```
diff --git a/utils/check-for-trailing-whitespace.sh b/utils/check-for-trailing-whitespace.sh
new file mode 100755
index 0000000..00be038
--- /dev/null
+++ b/utils/check-for-trailing-whitespace.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+cd .. || exit
+# print first
+grep -EHInr '( +)$' ./*
+
+var=$(grep -EHInr '( +)$' ./*)
+# then exit with fail if found
+if test -z "$var"; then
+  exit 0
+else
+  exit 1
+fi