added mypy-diff and mypy-commit targets to makefile (#1511)

* added mypy-diff and mypy-commit targets to makefile

.editorconfig

@@ -13,3 +13,5 @@ charset = utf-8
 [*.py]
 max_line_length = 128
 
+[Makefile]
+indent_style = tab

.gitignore

@@ -58,6 +58,7 @@ mypy
 types
 mypy.xml
 coverage
+.mypy-baseline
 
 # Duplicate Files for text_common package, copied by tests_common/copy_files_from_core.py
 tests_common/src/inmanta_tests/conftest.py

Makefile

@@ -25,9 +25,48 @@ pep8:
 	pip install -c requirements.txt pep8-naming flake8-black flake8-isort
 	flake8 src tests tests_common
 
-.PHONY: mypy
+.PHONY: mypy mypy-diff mypy-save
+RUN_MYPY=MYPYPATH=stubs:src python -m mypy --html-report mypy -p inmanta
+
 mypy:
-	MYPYPATH=stubs:src python -m mypy --html-report mypy -p inmanta
+	$(RUN_MYPY)
+
+# baseline file mypy-diff will compare to
+MYPY_BASELINE_FILE=.mypy-baseline
+# temporary file used to store most recent mypy run
+MYPY_TMP_FILE=.mypy-tmp
+# temporary file used to store baseline with line numbers filtered out
+MYPY_BASELINE_FILE_NO_LN_NB=$(MYPY_BASELINE_FILE).nolnnb
+# prepare file for diff: remove last 2 lines and filter out line numbers
+MYPY_DIFF_PREPARE=head -n -2 | sed 's/^\(.\+:\)[0-9]\+\(:\)/\1\2/'
+# read old/new line number (format +n for new or -n for old) from stdin and transform to old/new line
+MYPY_DIFF_FETCH_LINES=xargs -I{} sh -c 'sed -n -e "s/^/$(MYPY_SET_COLOUR)$$(echo {} | cut -c 1 -) /" -e "$$(echo {} | cut -c 2- -)p" $(MYPY_SELECT_FILE)'
+MYPY_SELECT_FILE=$$(if [[ "{}" == +* ]]; then echo $(MYPY_TMP_FILE); else echo $(MYPY_BASELINE_FILE); fi)
+MYPY_SET_COLOUR=$$(if [[ "{}" == +* ]]; then tput setaf 1; else tput setaf 2; fi)
+# diff line format options
+LFMT_LINE_NB=%dn
+LFMT_NEWLINE=%c'\\012'
+
+# compare mypy output with baseline file, show newly introduced and resolved type errors
+mypy-diff:
+	@ # run mypy and temporarily save result
+	@ $(RUN_MYPY) > $(MYPY_TMP_FILE) || true
+	@ # prepare baseline for diff and temporarily save result
+	@ cat $(MYPY_BASELINE_FILE) | $(MYPY_DIFF_PREPARE) > $(MYPY_BASELINE_FILE_NO_LN_NB) || true
+	@ # prepare most recent mypy output and run diff, returing +n for new lines and -n for old lines, where n is the line number
+	@ cat $(MYPY_TMP_FILE) | $(MYPY_DIFF_PREPARE) | diff $(MYPY_BASELINE_FILE_NO_LN_NB) - \
+		--new-line-format="+$(LFMT_LINE_NB)$(LFMT_NEWLINE)" \
+		--old-line-format="-$(LFMT_LINE_NB)$(LFMT_NEWLINE)" \
+		--unchanged-line-format='' \
+		--unidirectional-new-file \
+		| $(MYPY_DIFF_FETCH_LINES) \
+		|| true
+	@ # cleanup
+	@ rm -f $(MYPY_TMP_FILE) $(MYPY_BASELINE_FILE_NO_LN_NB)
+
+# save mypy output to baseline file
+mypy-save:
+	$(RUN_MYPY) > $(MYPY_BASELINE_FILE) || true
 
 .PHONY: test
 test: