cli: update command line arguments (breaking change)

This commit updates the CLI arguments to accept either a file containing
a json pointer expression, or an expression as a commandline argument:

    usage: jsonpointer [-h] (-f [POINTER_FILE] | -p [POINTER]) [--indent INDENT] [-v] FILE [FILE ...]

Without this commit

    jsonpointer "/a" a.json b.json

works fine, however using a file doesn't work:

    $ jsonpointer -f ptr.json a.json b.json
    usage: jsonpointer [-h] [-f [POINTER_FILE]] [--indent INDENT] [-v] [POINTER] FILE [FILE ...]
    jsonpointer: error: argument POINTER: not allowed with argument -f/--pointer-file

This commit also improves the usage message by explaining the mutually exclusive arguments,
adds tests for the changes, updates the documentation and adds a new CHANGELOG.md file.

Resolves #43

CHANGELOG.md

@@ -0,0 +1,8 @@
+# Change Log
+
+## x.y (unreleased)
+
+### Breaking Changes
+
+The `jsonpointer` commandline utility accepts either a file containing a JSON pointer expression (example: `jsonpointer -f ptr.json a.json b.json`) or
+the expression as a commandline argument (example: `jsonpointer -p "/a" a.json b.json`).

MANIFEST.in

@@ -1,4 +1,5 @@
 include AUTHORS
 include LICENSE.txt
 include README.md
+include CHANGELOG.md
 include tests.py

bin/jsonpointer

@@ -20,7 +20,7 @@ ptr_group.add_argument('-f', '--pointer-file', type=argparse.FileType('r'),
                        nargs='?',
                        help='File containing a JSON pointer expression')
 
-ptr_group.add_argument('POINTER',  type=str, nargs='?',
+ptr_group.add_argument('-p', '--pointer',  type=str, nargs='?',
                        help='A JSON pointer expression')
 
 parser.add_argument('FILE', type=argparse.FileType('r'), nargs='+',
@@ -39,8 +39,8 @@ def main():
 
 
 def parse_pointer(args):
-    if args.POINTER:
-        ptr = args.POINTER
+    if args.pointer:
+        ptr = args.pointer
     elif args.pointer_file:
         ptr = args.pointer_file.read().strip()
     else:

doc/commandline.rst

@@ -6,16 +6,19 @@ that can be used to resolve a JSON pointers on JSON files.
 
 The program has the following usage ::
 
-    usage: jsonpointer [-h] [--indent INDENT] [-v] POINTER FILE [FILE ...]
+    usage: jsonpointer [-h] (-f [POINTER_FILE] | -p [POINTER]) [--indent INDENT] [-v] FILE [FILE ...]
 
     Resolve a JSON pointer on JSON files
 
     positional arguments:
-      POINTER          File containing a JSON pointer expression
       FILE             Files for which the pointer should be resolved
 
     optional arguments:
       -h, --help       show this help message and exit
+      -f [POINTER_FILE], --pointer-file [POINTER_FILE]
+                       File containing a JSON pointer expression
+      -p [POINTER], --pointer [POINTER]
+                       A JSON pointer expression
       --indent INDENT  Indent output by n spaces
       -v, --version    show program's version number and exit
 
@@ -34,9 +37,9 @@ Example
 
     # inspect JSON pointer
     $ cat ptr.json
-    "/a"
+    /a
 
     # resolve JSON pointer
-    $ jsonpointer ptr.json a.json b.json
+    $ jsonpointer -f ptr.json a.json b.json
     [1, 2, 3]
     {"b": [1, 3, 4]}

test/a.json

@@ -0,0 +1 @@
+{ "a": [1, 2, 3] }

test/b.json

@@ -0,0 +1 @@
+{ "a": {"b": [1, 3, 4]}, "b": 1 }

test/ptr.json

@@ -0,0 +1 @@
+/a

tests.py

@@ -7,6 +7,7 @@
 import unittest
 import sys
 import copy
+import subprocess
 from jsonpointer import resolve_pointer, EndOfList, JsonPointerException, \
          JsonPointer, set_pointer
 
@@ -298,6 +299,19 @@ def test_mock_dict_raises_key_error(self):
         self.assertRaises(JsonPointerException, resolve_pointer, doc, '/root/1/2/3/4')
 
 
+class CommandLineTests(unittest.TestCase):
+    """ Tests the command line """
+
+    def test_file(self):
+        output = subprocess.check_output(["jsonpointer", "-f", "ptr.json", "a.json", "b.json"], cwd="test")
+        self.assertEqual(output, b'[1, 2, 3]\n{"b": [1, 3, 4]}\n')
+
+
+    def test_pointerarg(self):
+        output = subprocess.check_output(["jsonpointer", "-p", "/a", "a.json", "b.json"], cwd="test")
+        self.assertEqual(output, b'[1, 2, 3]\n{"b": [1, 3, 4]}\n')
+
+
 
 suite = unittest.TestSuite()
 suite.addTest(unittest.makeSuite(SpecificationTests))
@@ -306,6 +320,7 @@ def test_mock_dict_raises_key_error(self):
 suite.addTest(unittest.makeSuite(ToLastTests))
 suite.addTest(unittest.makeSuite(SetTests))
 suite.addTest(unittest.makeSuite(AltTypesTests))
+suite.addTest(unittest.makeSuite(CommandLineTests))
 
 modules = ['jsonpointer']