Generate quickest Maven script for the pending changes in a Git checkout

genMavenImpactScript.py

#!/bin/python3

# See https://paulhammant.com/2019/10/20/quicker-local-maven-builds

import sh, os
from pathlib import Path

log = sh.git.log("--oneline", "--no-color", "--decorate=short", _tty_out=False)
hashLine = ""
for line in log.split("\n"):
    if ' (origin/master,' in line:
        hashLine = line
        break
    if 'master, origin/master' in line:
        hashLine = line
        break
        
if (len(hashLine) is 0):
    print("Could not determine origin/master SHA1")
    exit(1)
originHash = hashLine.split(" ")[0]

diffFiles = sh.git.diff("--name-status", originHash, _tty_out=False)
allModules = []

for filename in Path('.').glob('**/pom.xml'):
    allModules.append(str(filename).split("/pom.xml")[0])

allModulesWithSourceTrees = []

for filename in Path('.').glob('**/src/main'):
    srcDir = str(filename).split("/src/main")[0]
    if srcDir in allModules and srcDir not in allModulesWithSourceTrees:
        allModulesWithSourceTrees.append(srcDir)

impactedProdModules = []
impactedTestModules = []

for diffFile in diffFiles:
    file = diffFile.split("\t")[1].strip()
    for m in allModulesWithSourceTrees:
        if file.startswith(m) and "src/test/" not in file and m not in impactedProdModules:
            impactedProdModules.append(m)
            impactedTestModules.append(m)
        if file.startswith(m) and "src/test/" in file and m not in impactedTestModules:
            impactedTestModules.append(m)
        
with open(".mvnCommands.sh", 'w') as out:
    out.write("#!/bin/sh\n\nset -e\n\n")
    out.write("mvn install -DskipTests -pl " + ",".join(impactedProdModules) + "\n\n")
    out.write("mvn test -Dmaven.main.skip -pl " + ",".join(impactedTestModules) + "\n\n")
    
os.chmod(".mvnCommands.sh", 0o775)

print(".mvnCommands.sh updated")