Linting pre-commit hook (#787)

* pre-commit hook and reqs

* Updated pre-commit file

* Added hook setup file

* Updated linting step to only use yapf and only lint staged files

* Removed redundant yapf from environment

* Updated developer readme on github

* Edited dev readme

* Updated web documentation

* Updated installation.rst

* Deleted extra whitespace

* Added hook_setup confirmation and updated documentation

* Standardized shell files

* Updated documentation

* updated pre-commit hook

Co-authored-by: Priti Ashvin Shah <[email protected]>

README_developers.md

@@ -125,5 +125,13 @@ If you are planning to develop the qiskit metal codebase, you need extra package
 ```
 python -m pip install -r requirements-dev.txt
 ```
-You'll want to also use these instructions to [setup user environment](/docs/NEW_DEVELOPER_SETUP.md)
+You may also want to also use these instructions to [setup user environment](/docs/NEW_DEVELOPER_SETUP.md)
+
+#### Setting up precommit hooks
+
+If are planning on committing, you can run the following in the root of your project to link the available precommit hooks.
+```
+./hook_setup
+```
+Please make sure the command is run from the same shell you plan on using to commit. If running on Windows, please make sure that this script is run from git-bash or another Linux-style shell. Currently, the precommit hook will check for yapf formatting.
 

docs/installation.rst

@@ -185,6 +185,17 @@ Here are some things to consider when setting up a development environment:
 
 * Library errors when activating conda environments, or initializing jupyter notebook/lab, indicate a conflict between python libraries in the base and sub environments. Go ahead and manually delete the library from the base environment `site-packages` folder, shows in the error message. You might need to reinstall them in the sub environment, or create a new one.
 
+--------------------------
+Setting up precommit hooks
+--------------------------
+
+If are planning on committing, you can run the following in the root of your project to link the available precommit hooks.
+::
+
+    ./hook_setup
+
+Please make sure the command is run from the same shell you plan on using to commit. If running on Windows, please make sure that this script is run from git-bash or another Linux-style shell. Currently, the precommit hook will check for yapf formatting.
+
 =============
 Common Issues
 =============

hook_setup.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+ln -s -f ../../hooks/pre-commit .git/hooks/pre-commit
+ret=$?
+if [[ $ret != 0 ]]; then
+    echo "Linking hooks failed with rc $ret"
+else
+    echo "Linking hooks succeeded!"
+fi

hooks/pre-commit

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+echo "Checking dependencies"
+which yapf &> /dev/null
+ret=$?
+if [[ $ret != 0 ]]; then
+    echo "Please install yapf to use pre-commit hook"
+    exit 1
+else
+    echo "All dependencies present"
+fi
+
+echo "Begin linting step using yapf formatting"
+linterrorfound=0
+for stagedfile in $(git diff --name-only --cached | grep .*.py)
+do
+    yapf --diff --style .style.yapf $stagedfile
+    ret=$?
+    if [[ $ret != 0 ]]; then
+        linterrorfound=1
+        echo ">>> Errors in file $stagedfile"
+    fi
+done
+
+if [[ $linterrorfound == 1 ]]; then
+    echo "Please fix linting errors before committing"
+    exit 1
+else
+    echo "Linting successful"
+fi
+
+echo "Python linting validation completed!"
+exit 0