Tests: Add a lint check for trailing whitespace

[meshcollider]

This is a new attempt at #11005

Addressed nits, excluded imported dependencies, squashed the original commits, and added a test for tab characters in the *.cpp *.h *.md *.py *.sh files too as per @practicalswift suggestion

[practicalswift]

utACK 258094a

[meshcollider]

Fixed a mis-copied comment in the tab character check which was referring to whitespace again

[sipa]

This doesn't sound like correct English to me (but I'm not a native speaker myself). Use "instead of spaces" perhaps?

[meshcollider]

Yeah, I don't think it's technically wrong but it doesn't sound quite right, yours sounds better. Fixed.

[maflcko]

This needs to be guarded by TRAVIS_COMMIT_RANGE if you fail on -z $TRAVIS_COMMIT_RANGE, no?

[meshcollider]

I'm not even sure if I should have changed it to fail, should it just exit quietly if there's no commit range?

[maflcko]

Actually this should be fine, as TRAVIS_COMMIT_RANGE should never be empty according to the travis doc. (It is only empty for branches with a single commit, which we don't have)

[mess110]

I can't manage to run the script. Am I calling it wrong?

TRAVIS_COMMIT_RANGE=50fae68d416b4b8ec4ca192923dfd5ae9ea42773...b3d6fc654770e3b4d2f82e8d77e531df9e522982 ./contrib/devtools/lint-all.sh
fatal: There is nothing to exclude from by :(exclude) patterns.
Perhaps you forgot to add either ':/' or '.' ?

I got the commit range from https://travis-ci.org/bitcoin/bitcoin/jobs/272143045

I get the same if I run

TRAVIS_COMMIT_RANGE=50fae68d416b4b8ec4ca192923dfd5ae9ea42773...b3d6fc654770e3b4d2f82e8d77e531df9e522982 git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/"

This works:

TRAVIS_COMMIT_RANGE=50fae68d416b4b8ec4ca192923dfd5ae9ea42773...b3d6fc654770e3b4d2f82e8d77e531df9e522982 git diff -U0 "${TRAVIS_COMMIT_RANGE}"

[meshcollider]

@mess110 my guess is that you have a different version of git which doesn't assume all files to be included if only excludes are given, but I've updated the commit to (hopefully) fix it for you

[mess110]

Thanks, that was it indeed.

ACK b8c0cfa

[practicalswift]

utACK b8c0cfae6d6f39fe38dcfec229f3824a5af44b29

[maflcko]

utACK b8c0cfae6d6f39fe38dcfec229f3824a5af44b29

[jnewbery]

Tested ACK. I've tested locally that both checks work, and that the src/leveldb/ exclusion also works.

It'd be helpful to also print out the @@ line showing the line number where the whitespace was introduced. Something like:

diff --git a/contrib/devtools/lint-whitespace.sh b/contrib/devtools/lint-whitespace.sh
index 5bea86a..8a065fe 100755
--- a/contrib/devtools/lint-whitespace.sh
+++ b/contrib/devtools/lint-whitespace.sh
@@ -40,0 +41,2 @@ if showdiff | grep -E -q '^\+.*\s+$'; then
+    elif [[ "$line" =~ ^@@ ]]; then
+      LINENUMBER="$line"
@@ -46,0 +49 @@ if showdiff | grep -E -q '^\+.*\s+$'; then
+        echo "$LINENUMBER"
@@ -51 +54 @@ if showdiff | grep -E -q '^\+.*\s+$'; then
-  done < <(showdiff | grep -E '^(diff --git |\+.*\s+$)')
+  done < <(showdiff | grep -E '^(diff --git |@@|\+.*\s+$)')
@@ -64,0 +68,2 @@ if showcodediff | grep -P -q '^\+.*\t'; then
+    elif [[ "$line" =~ ^@@ ]]; then
+      LINENUMBER="$line"
@@ -70,0 +76 @@ if showcodediff | grep -P -q '^\+.*\t'; then
+        echo "$LINENUMBER"
@@ -75 +81 @@ if showcodediff | grep -P -q '^\+.*\t'; then
-  done < <(showcodediff | grep -P '^(diff --git |\+.*\t)')
+  done < <(showcodediff | grep -P '^(diff --git |@@|\+.*\t)')

should do it. This only prints out the line number for the first match in each file, but I think that's ok.

[jnewbery]

Perhaps add help text here explaining how to run locally:

  echo "To run locally, use:"
  echo "TRAVIS_COMMIT_RANGE='<commit range>' .lint-whitespace.sh"
  echo "eg:"
  echo "TRAVIS_COMMIT_RANGE='47ba2c3...ee50c9e' .lint-whitespace.sh"

[meshcollider]

Rebased on master to fix merge conflict and addressed @jnewbery's comments, thanks!

[maflcko]

re-utACK 1f379b1