ci: make the whitespace report optional

The `check-whitespace` CI job generates a formatted output file
containing whitespace error information. As not all CI providers support
rendering a formatted summary, make its generation optional.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/ci/check-whitespace.sh b/ci/check-whitespace.sh
index 9cc496da401decf4945bb0839baba9375b73cc54..db399097a52db65c3a8d00830e578049de96801d 100755 (executable)
--- a/ci/check-whitespace.sh
+++ b/ci/check-whitespace.sh
@@ -1,9 +1,20 @@
 #!/usr/bin/env bash
+#
+# Check that commits after a specified point do not contain new or modified
+# lines with whitespace errors. An optional formatted summary can be generated
+# by providing an output file path and url as additional arguments.
+#
 
 baseCommit=$1
 outputFile=$2
 url=$3
 
+if test "$#" -ne 1 && test "$#" -ne 3
+then
+       echo "USAGE: $0 <BASE_COMMIT> [<OUTPUT_FILE> <URL>]"
+       exit 1
+fi
+
 problems=()
 commit=
 commitText=
@@ -56,19 +67,29 @@ then
                goodParent=${baseCommit: 0:7}
        fi
 
-       echo "🛑 Please review the Summary output for further information."
-       echo "### :x: A whitespace issue was found in one or more of the commits." >"$outputFile"
-       echo "" >>"$outputFile"
-       echo "Run these commands to correct the problem:" >>"$outputFile"
-       echo "1. \`git rebase --whitespace=fix ${goodParent}\`" >>"$outputFile"
-       echo "1. \`git push --force\`" >>"$outputFile"
-       echo " " >>"$outputFile"
-       echo "Errors:" >>"$outputFile"
+       echo "A whitespace issue was found in onen of more of the commits."
+       echo "Run the following command to resolve whitespace issues:"
+       echo "git rebase --whitespace=fix ${goodParent}"
+
+       # If target output file is provided, write formatted output.
+       if test -n "$outputFile"
+       then
+               echo "🛑 Please review the Summary output for further information."
+               (
+                       echo "### :x: A whitespace issue was found in one or more of the commits."
+                       echo ""
+                       echo "Run these commands to correct the problem:"
+                       echo "1. \`git rebase --whitespace=fix ${goodParent}\`"
+                       echo "1. \`git push --force\`"
+                       echo ""
+                       echo "Errors:"
 
-       for i in "${problems[@]}"
-       do
-               echo "${i}" >>"$outputFile"
-       done
+                       for i in "${problems[@]}"
+                       do
+                               echo "${i}"
+                       done
+               ) >"$outputFile"
+       fi
 
        exit 2
 fi