[#215][Python/Pre-commit] Simplify the mypy Driver.

pre-commit/mypy.sh

@@ -3,51 +3,41 @@
 # NOTE: We can't simply run `mypy` for the whole repo because there is a
 # bug with modules having duplicate names.
 # See https://github.com/python/mypy/issues/10428.
-# Instead, we define the prompt manually, to run at one repo at a time.
-# We are currently in the process of migrating from the dynamic, slow,
-# tedious, `type_enforced` to `mypy`.
-# For each project that gets migrated, we should add a line to execute
-# `mypy` on it here.
-
-# NOTE: To guard against developers forgetting to include their Python
-# projects in this list, we also have a generic line that runs `mypy`
-# against all files that don't belong to any of the projects.
-# Thus, every Python file will be either part of a project (in which case
-# it should be ignored by the generic prompt), or should be covered by
-# the generic prompt.
+# Instead, we define the prompt manually, to run at one subproject at a time.
 
 set -o errexit  # Exit upon encountering a failure.
 set -o nounset  # Consider an undefined variable to be an error.
 
 source .helpers
 
 _mypy() {
-  PREFIX="${1}"
-  MATCHES="$(echo "${@:2}" | tr ' ' '\n' | _grep "^${PREFIX}")"
-  if [ -n "${MATCHES}" ]; then
-    # shellcheck disable=SC2046
-    mypy $(echo "${MATCHES}" | tr '\n' ' ') --check-untyped-defs
-  fi
+  # shellcheck disable=SC2046
+  mypy $(echo "${@}" | tr '\n' ' ') --check-untyped-defs
 }
 
-# TODO: (#215) Maintain one list of projects instead of duplicating it.
-_mypy "bible" "${@}"
-_mypy "dictionary/copticsite.com" "${@}"
-_mypy "dictionary/kellia.uni-goettingen.de" "${@}"
-_mypy "dictionary/marcion.sourceforge.net" "${@}"
-_mypy "flashcards" "${@}"
-_mypy "morphology" "${@}"
-_mypy "site" "${@}"
+SUBPROJECTS=(
+  "bible"
+  "dictionary/copticsite.com"
+  "dictionary/kellia.uni-goettingen.de"
+  "dictionary/marcion.sourceforge.net"
+  "flashcards"
+  "morphology"
+  "site"
+)
 
-NONMATCHES=$(echo "${@}" | tr ' ' '\n' \
-  | _grep --invert "^bible/" \
-  | _grep --invert "^dictionary/copticsite.com/" \
-  | _grep --invert "^dictionary/kellia.uni-goettingen.de/" \
-  | _grep --invert "^dictionary/marcion.sourceforge.net/" \
-  | _grep --invert "^flashcards/" \
-  | _grep --invert "^morphology/" \
-  | _grep --invert "^site/")
+# Run `mypy` once against each of the prefixes above.
+NONMATCHES=$(echo "${@}" | tr ' ' '\n')
+for PREFIX in "${SUBPROJECTS[@]}"; do
+  MATCHES="$(echo "${@}" | tr ' ' '\n' | _grep "^${PREFIX}")"
+  if [ -n "${MATCHES}" ]; then
+    # NOTE: For a matching prefix, we run `mypy` against the entire subtree,
+    # not just the affected files.
+    _mypy "${PREFIX}"
+  fi
+  NONMATCHES=$(echo "${NONMATCHES}" | grep --invert "^${PREFIX}/")
+done
+
+# Run against the affected files that didn't match any of the prefixes above.
 if [ -n "${NONMATCHES}" ]; then
-  # shellcheck disable=SC2046
-  mypy $(echo "${NONMATCHES}" | tr '\n' ' ') --check-untyped-defs
+  _mypy "${NONMATCHES}"
 fi