a proof-of-concept for coverage-goals

Author: nedbat

lab/goals.py

@@ -0,0 +1,91 @@
+"""\
+Check coverage goals.
+
+Use `coverage json` to get a coverage.json file, then run this tool
+to check goals for subsets of files.
+
+Patterns can use '**/foo*.py' to find files anywhere in the project,
+and '!**/something.py' to exclude files matching a pattern.
+
+--file will check each file individually for the required coverage.
+--group checks the entire group collectively.
+
+"""
+
+import argparse
+import json
+import sys
+
+from wcmatch import fnmatch as wcfnmatch    # python -m pip install wcmatch
+
+from coverage.results import Numbers    # Note: an internal class!
+
+
+def get_data():
+    with open("coverage.json") as j:
+        return json.load(j)
+
+def select_files(files, pat):
+    flags = wcfnmatch.NEGATE | wcfnmatch.NEGATEALL
+    selected = [f for f in files if wcfnmatch.fnmatch(f, pat, flags=flags)]
+    return selected
+
+def total_for_files(data, files):
+    total = Numbers(precision=3)
+    for f in files:
+        sel_summ = data["files"][f]["summary"]
+        total += Numbers(
+            n_statements=sel_summ["num_statements"],
+            n_excluded=sel_summ["excluded_lines"],
+            n_missing=sel_summ["missing_lines"],
+            n_branches=sel_summ["num_branches"],
+            n_partial_branches=sel_summ["num_partial_branches"],
+            n_missing_branches=sel_summ["missing_branches"],
+            )
+
+    return total
+
+def main(argv):
+    parser = argparse.ArgumentParser(__doc__)
+    parser.add_argument("--file", "-f", action="store_true", help="Check each file individually")
+    parser.add_argument("--group", "-g", action="store_true", help="Check a group of files")
+    parser.add_argument("--verbose", "-v", action="store_true", help="Be chatty about what's happening")
+    parser.add_argument("goal", type=float, help="Coverage goal")
+    parser.add_argument("pattern", type=str, nargs="+", help="Patterns to check")
+    args = parser.parse_args(argv)
+
+    if args.file and args.group:
+        print("Can't use --file and --group together")
+        return 1
+    if not (args.file or args.group):
+        print("Need either --file or --group")
+        return 1
+
+    data = get_data()
+    all_files = list(data["files"].keys())
+    selected = select_files(all_files, args.pattern)
+
+    ok = True
+    if args.group:
+        total = total_for_files(data, selected)
+        pat_nice = ",".join(args.pattern)
+        result = f"Coverage for {pat_nice} is {total.pc_covered_str}"
+        if total.pc_covered < args.goal:
+            print(f"{result}, below {args.goal}")
+            ok = False
+        elif args.verbose:
+            print(result)
+    else:
+        for fname in selected:
+            total = total_for_files(data, [fname])
+            result = f"Coverage for {fname} is {total.pc_covered_str}"
+            if total.pc_covered < args.goal:
+                print(f"{result}, below {args.goal}")
+                ok = False
+            elif args.verbose:
+                print(result)
+
+    return 0 if ok else 2
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))