enhancement: JSON variable file support

atest/robot/variables/json_variable_file.robot

@@ -0,0 +1,70 @@
+*** Settings ***
+Suite Setup      Run Tests    --variablefile ${VARDIR}/cli.json -V ${VARDIR}/cli2.json --pythonpath ${VARDIR}
+...              variables/json_variable_file.robot
+Force Tags       require-json
+Resource         atest_resource.robot
+
+*** Variables ***
+${VARDIR}        ${DATADIR}/../testresources/res_and_var_files
+
+*** Test Cases ***
+Valid JSON file
+    Check Test Case    ${TESTNAME}
+
+Non-ASCII strings
+    Check Test Case    ${TESTNAME}
+
+Dictionary is dot-accessible
+    Check Test Case    ${TESTNAME}
+
+Nested dictionary is dot-accessible
+    Check Test Case    ${TESTNAME}
+
+Dictionary inside list is dot-accessible
+    Check Test Case    ${TESTNAME}
+
+JSON file in PYTHONPATH
+    Check Test Case    ${TESTNAME}
+
+Import Variables keyword
+    Check Test Case    ${TESTNAME}
+
+JSON file from CLI
+    Check Test Case    ${TESTNAME}
+
+Invalid JSON file
+    Processing should have failed    0    4    invalid.json
+    ...    ${EMPTY}
+    ...    JSONDecodeError*
+
+Non-mapping JSON file
+    Processing should have failed    1    5    non_dict.json
+    ...    ${EMPTY}
+    ...    JSON variable file must be a mapping, got list.
+
+JSON files do not accept arguments
+    Processing should have failed    2    6    valid.json
+    ...    with arguments ? arguments | not | accepted ?${SPACE}
+    ...    JSON variable files do not accept arguments.
+
+Non-existing JSON file
+    Importing should have failed    3    7
+    ...    Variable file 'non_existing.Json' does not exist.
+
+JSON with invalid encoding
+    Processing should have failed    4    8    invalid_encoding.json
+    ...    ${EMPTY}
+    ...    UnicodeDecodeError*
+
+*** Keywords ***
+Processing should have failed
+    [Arguments]    ${index}    ${lineno}    ${file}    ${arguments}    ${error}
+    ${path} =    Normalize Path    ${DATADIR}/variables/${file}
+    Importing should have failed    ${index}    ${lineno}
+    ...    Processing variable file '${path}' ${arguments}failed:
+    ...    ${error}
+
+Importing should have failed
+    [Arguments]    ${index}    ${lineno}    @{error}
+    Error In File    ${index}    variables/json_variable_file.robot    ${lineno}
+    ...    @{error}

atest/testdata/variables/invalid.json

@@ -0,0 +1 @@
+name: "jack"

atest/testdata/variables/invalid_encoding.json

@@ -0,0 +1,5 @@
+{
+  "encoding": "latin-1",
+  "expected": "utf-8",
+  "non-ascii": "hyv�� y�t�!"
+}

atest/testdata/variables/json_variable_file.robot

@@ -0,0 +1,53 @@
+*** Settings ***
+Variables        valid.json
+Variables        pythonpath.json
+Variables        ./invalid.json
+Variables        ..${/}variables${/}non_dict.json
+Variables        valid.json    arguments    not    accepted
+Variables        non_existing.Json
+Variables        invalid_encoding.json
+Test Template    Should Be Equal
+
+*** Variables ***
+@{EXPECTED LIST}      one    ${2}
+&{EXPECTED DICT}      a=1    b=${2}    3=${EXPECTED LIST}    key with spaces=value with spaces
+
+
+*** Test Cases ***
+Valid JSON file
+    ${STRING}     Hello, YAML!
+    ${INTEGER}    ${42}
+    ${FLOAT}      ${3.14}
+    ${LIST}       ${EXPECTED LIST}
+    ${DICT}       ${EXPECTED DICT}
+    ${BOOL}    ${TRUE}
+    ${NULL}    ${NULL}
+
+Non-ASCII strings
+    ${NON}    äscii
+    ${NÖN}    äscii
+
+Dictionary is dot-accessible
+    ${DICT.a}                1
+    ${DICT.b}                ${2}
+
+Nested dictionary is dot-accessible
+    ${NESTED DICT.dict}      ${EXPECTED DICT}
+    ${NESTED DICT.dict.a}    1
+    ${NESTED DICT.dict.b}    ${2}
+
+Dictionary inside list is dot-accessible
+    ${LIST WITH DICT[1].key}               value
+    ${LIST WITH DICT[2].dict}              ${EXPECTED DICT}
+    ${LIST WITH DICT[2].nested[0].leaf}    value
+
+JSON file in PYTHONPATH
+    ${JSON FILE IN PYTHONPATH}    ${TRUE}
+
+Import Variables keyword
+    [Setup]    Import Variables    ${CURDIR}/valid2.json
+    ${VALID 2}    imported successfully
+
+JSON file from CLI
+    ${JSON FILE FROM CLI}    woot!
+    ${JSON FILE FROM CLI2}     kewl!

atest/testdata/variables/non_dict.json

@@ -0,0 +1,6 @@
+[
+  "Not dictionary",
+  {
+    "true": "top-level"
+  }
+]

atest/testdata/variables/valid.json

@@ -0,0 +1,55 @@
+{
+  "string": "Hello, YAML!",
+  "non": "äscii",
+  "nön": "äscii",
+  "integer": 42,
+  "float": 3.14,
+  "bool": true,
+  "null": null,
+  "list": [
+    "one",
+    2
+  ],
+  "dict": {
+    "a": "1",
+    "b": 2,
+    "3": [
+      "one",
+      2
+    ],
+    "key with spaces": "value with spaces"
+  },
+  "nested dict": {
+    "dict": {
+      "a": "1",
+      "b": 2,
+      "3": [
+        "one",
+        2
+      ],
+      "key with spaces": "value with spaces"
+    }
+  },
+  "list with dict": [
+    "scalar",
+    {
+      "key": "value"
+    },
+    {
+      "dict": {
+        "a": "1",
+        "b": 2,
+        "3": [
+          "one",
+          2
+        ],
+        "key with spaces": "value with spaces"
+      },
+      "nested": [
+        {
+          "leaf": "value"
+        }
+      ]
+    }
+  ]
+}

atest/testdata/variables/valid2.json

@@ -0,0 +1,3 @@
+{
+  "valid 2": "imported successfully"
+}

atest/testresources/res_and_var_files/cli.json

@@ -0,0 +1,3 @@
+{
+  "json file from cli": "woot!"
+}

atest/testresources/res_and_var_files/cli2.json

@@ -0,0 +1,3 @@
+{
+  "json file from cli2": "kewl!"
+}

atest/testresources/res_and_var_files/pythonpath.json

@@ -0,0 +1,3 @@
+{
+  "json file in pythonpath":    true
+}

src/robot/running/namespace.py

@@ -37,7 +37,7 @@
 class Namespace:
     _default_libraries = ('BuiltIn', 'Reserved', 'Easter')
     _library_import_by_path_ends = ('.py', '/', os.sep)
-    _variables_import_by_path_ends = _library_import_by_path_ends + ('.yaml', '.yml')
+    _variables_import_by_path_ends = _library_import_by_path_ends + ('.yaml', '.yml') + ('.json',)
 
     def __init__(self, variables, suite, resource, languages):
         LOGGER.info(f"Initializing namespace for suite '{suite.longname}'.")

src/robot/variables/filesetter.py

@@ -15,6 +15,7 @@
 
 import inspect
 import io
+import json
 try:
     import yaml
 except ImportError:
@@ -43,6 +44,8 @@ def _import_if_needed(self, path_or_variables, args=None):
                     % (path_or_variables, args))
         if path_or_variables.lower().endswith(('.yaml', '.yml')):
             importer = YamlImporter()
+        elif path_or_variables.endswith(('json',)):
+            importer = JsonImporter()
         else:
             importer = PythonImporter()
         try:
@@ -147,3 +150,27 @@ def _validate(self, name, value):
         if name[0] == '&' and not is_dict_like(value):
             raise DataError("Invalid variable '%s': Expected dict-like value, "
                             "got %s." % (name, type_name(value)))
+
+
+class JsonImporter:
+    def import_variables(self, path, args=None):
+        if args:
+            raise DataError('JSON variable files do not accept arguments.')
+        variables = self._import(path)
+        return [('${%s}' % name, self._dot_dict(value))
+                for name, value in variables]
+
+    def _import(self, path):
+        with io.open(path, encoding='UTF-8') as stream:
+            variables = json.load(stream)
+        if not is_dict_like(variables):
+            raise DataError('JSON variable file must be a mapping, got %s.'
+                            % type_name(variables))
+        return variables.items()
+
+    def _dot_dict(self, value):
+        if is_dict_like(value):
+            return DotDict((k, self._dot_dict(v)) for k, v in value.items())
+        if is_list_like(value):
+            return [self._dot_dict(v) for v in value]
+        return value

src/robot/variables/scopes.py

@@ -162,7 +162,7 @@ def as_dict(self, decoration=True):
 
 
 class GlobalVariables(Variables):
-    _import_by_path_ends = ('.py', '/', os.sep, '.yaml', '.yml')
+    _import_by_path_ends = ('.py', '/', os.sep, '.yaml', '.yml', '.json')
 
     def __init__(self, settings):
         super().__init__()