Merge #13281: test: Move linters to test/lint, add readme

fa3c910bfe test: Move linters to test/lint, add readme (MarcoFalke)

Pull request description:

  This moves the checks and linters from `devtools` to a subfolder in `test`. (Motivated by my opinion that the dev tools are mostly for generating code and updating the repo whereas the linters are read-only checks.)

  Also, adds a readme to clarify that checks and linters are only meant to prevent bugs and user facing issues, not merely stylistic preference or inconsistencies. (This is motivated by the diversity in developers and work flows as well as existing code styles. It would be too disruptive to change all existing code to a single style or too burdensome to force all developers to adhere to a single style. Also note that our style guide is changing, so locking in at the wrong style "too early" would only waste resources.)

Tree-SHA512: 9b10e89f2aeaf0c8a9ae248aa891d74e0abf0569f8e5dfd266446efa8bfaf19f0ea0980abf0b0b22f0d8416ee90d7435d21a9f9285b66df43f370b7979173406

.travis.yml

@@ -85,17 +85,17 @@ jobs:
             - python3-pip
             - shellcheck
       install:
-        - if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then travis_retry pip3 install flake8 --user; fi
+        - travis_retry pip3 install flake8 --user
       before_script:
         - git fetch --unshallow
-        - if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then contrib/devtools/commit-script-check.sh $TRAVIS_COMMIT_RANGE; fi
-        - contrib/devtools/git-subtree-check.sh src/crypto/ctaes
-        - contrib/devtools/git-subtree-check.sh src/secp256k1
-        - contrib/devtools/git-subtree-check.sh src/univalue
-        - contrib/devtools/git-subtree-check.sh src/leveldb
-        - contrib/devtools/check-doc.py
-        - contrib/devtools/check-rpc-mappings.py .
-        - if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then contrib/devtools/lint-all.sh; fi
+        - if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then test/lint/commit-script-check.sh $TRAVIS_COMMIT_RANGE; fi
+        - test/lint/git-subtree-check.sh src/crypto/ctaes
+        - test/lint/git-subtree-check.sh src/secp256k1
+        - test/lint/git-subtree-check.sh src/univalue
+        - test/lint/git-subtree-check.sh src/leveldb
+        - test/lint/check-doc.py
+        - test/lint/check-rpc-mappings.py .
+        - test/lint/lint-all.sh
       script:
         - if [ "$TRAVIS_REPO_SLUG" = "bitcoin/bitcoin" -a "$TRAVIS_PULL_REQUEST" = "false" ]; then while read LINE; do travis_retry gpg --keyserver hkp://subset.pool.sks-keyservers.net --recv-keys $LINE; done < contrib/verify-commits/trusted-keys; fi
         - if [ "$TRAVIS_REPO_SLUG" = "bitcoin/bitcoin" -a "$TRAVIS_EVENT_TYPE" = "cron" ]; then travis_wait 30 contrib/verify-commits/verify-commits.sh; fi

contrib/devtools/README.md

@@ -93,23 +93,6 @@ example:
 BUILDDIR=$PWD/build contrib/devtools/gen-manpages.sh
 ```
 
-git-subtree-check.sh
-====================
-
-Run this script from the root of the repository to verify that a subtree matches the contents of
-the commit it claims to have been updated to.
-
-To use, make sure that you have fetched the upstream repository branch in which the subtree is
-maintained:
-* for `src/secp256k1`: https://github.com/bitcoin-core/secp256k1.git (branch master)
-* for `src/leveldb`: https://github.com/bitcoin-core/leveldb.git (branch bitcoin-fork)
-* for `src/univalue`: https://github.com/bitcoin-core/univalue.git (branch master)
-* for `src/crypto/ctaes`: https://github.com/bitcoin-core/ctaes.git (branch master)
-
-Usage: `git-subtree-check.sh DIR (COMMIT)`
-
-`COMMIT` may be omitted, in which case `HEAD` is used.
-
 github-merge.py
 ===============
 

doc/developer-notes.md

@@ -647,7 +647,7 @@ Others are external projects without a tight relationship with our project.  Cha
 be sent upstream but bugfixes may also be prudent to PR against Bitcoin Core so that they can be integrated
 quickly.  Cosmetic changes should be purely taken upstream.
 
-There is a tool in contrib/devtools/git-subtree-check.sh to check a subtree directory for consistency with
+There is a tool in `test/lint/git-subtree-check.sh` to check a subtree directory for consistency with
 its upstream repository.
 
 Current subtrees include:
@@ -778,7 +778,7 @@ To create a scripted-diff:
     - `-BEGIN VERIFY SCRIPT-`
     - `-END VERIFY SCRIPT-`
 
-The scripted-diff is verified by the tool `contrib/devtools/commit-script-check.sh`
+The scripted-diff is verified by the tool `test/lint/commit-script-check.sh`
 
 Commit [`bb81e173`](https://github.com/bitcoin/bitcoin/commit/bb81e173) is an example of a scripted-diff.
 

test/functional/README.md

@@ -20,6 +20,8 @@ don't have test cases for.
 - Where possible, try to adhere to [PEP-8 guidelines](https://www.python.org/dev/peps/pep-0008/)
 - Use a python linter like flake8 before submitting PRs to catch common style
   nits (eg trailing whitespace, unused imports, etc)
+- See [the python lint script](/test/lint/lint-python.sh) that checks for violations that
+  could lead to bugs and issues in the test code.
 - Avoid wildcard imports where possible
 - Use a module-level docstring to describe what the test is testing, and how it
   is testing it.

test/lint/README.md

@@ -0,0 +1,29 @@
+This folder contains lint scripts.
+
+check-doc.py
+============
+Check for missing documentation of command line options.
+
+commit-script-check.sh
+======================
+Verification of [scripted diffs](/doc/developer-notes.md#scripted-diffs).
+
+git-subtree-check.sh
+====================
+Run this script from the root of the repository to verify that a subtree matches the contents of
+the commit it claims to have been updated to.
+
+To use, make sure that you have fetched the upstream repository branch in which the subtree is
+maintained:
+* for `src/secp256k1`: https://github.com/bitcoin-core/secp256k1.git (branch master)
+* for `src/leveldb`: https://github.com/bitcoin-core/leveldb.git (branch bitcoin-fork)
+* for `src/univalue`: https://github.com/bitcoin-core/univalue.git (branch master)
+* for `src/crypto/ctaes`: https://github.com/bitcoin-core/ctaes.git (branch master)
+
+Usage: `git-subtree-check.sh DIR (COMMIT)`
+
+`COMMIT` may be omitted, in which case `HEAD` is used.
+
+lint-all.sh
+===========
+Calls other scripts with the `lint-` prefix.