add deps checks

README.md

@@ -1,2 +1,15 @@
 # elm-ops-tooling
 Tooling for Elm ops
+
+
+## elm_deps_check
+
+Sometimes we need to make sure that two different exact-dependencies are the same. This is the case when you have a parent project, and a test project where the parent project dependencies are a sub list of test project.
+
+Usage:
+
+```bash
+
+python elm-stuff/exact-dependencies.json tests/elm-stuff/exact-dependencies.json
+
+```

elm_deps_check.py

@@ -0,0 +1,52 @@
+#! /usr/bin/env python
+from __future__ import print_function
+
+import sys
+
+import json
+
+
+def have_matching_versions(top_level_file, spec_file):
+    """ first file should be the top level elm-package
+        second file should be the spec file
+    """
+
+    with open(top_level_file) as f:
+        top_level = json.loads(f.read())
+        print(top_level_file, json.dumps(top_level, sort_keys=True, indent=4))
+
+    with open(spec_file) as f:
+        spec = json.loads(f.read())
+        print(spec_file, json.dumps(spec, sort_keys=True, indent=4))
+
+    errors = []
+
+    for (package_name, package_version) in top_level.items():
+        if package_name not in spec:
+            errors.append('Package {package_name} not found in {spec_file}, but was found in {top_level_file}'.format(
+                package_name=package_name, spec_file=spec_file, top_level_file=top_level_file)
+            )
+        elif spec[package_name] != package_version:
+            errors.append('Package version mismatch for'
+                ' {package_name}!\n\n {top_level_file} had {package_version}\n {spec_file} had {other_package_version}'.format(
+                    package_version=package_version, package_name=package_name, top_level_file=top_level_file,
+                    spec_file=spec_file, other_package_version=spec[package_name])
+                )
+
+    if len(errors) > 0:
+        print('FAILED due to elm-deps mismatch, errors:')
+        print('\n'.join(errors))
+        return False
+    else:
+        print('Matching deps!')
+        return True
+
+
+if __name__ == '__main__':
+    if len(sys.argv) > 2:
+        top_level_file = sys.argv[1]
+        spec_file = sys.argv[2]
+
+        if not have_matching_versions(top_level_file, spec_file):
+            sys.exit(1)
+