Merge pull request #19 from lark-parser/python_tests

Added python tests

Author: erezsh

.github/workflows/node.js.yml

@@ -28,4 +28,13 @@ jobs:
         cache: 'npm'
     - run: npm ci
     - run: npm run build --if-present
-    - run: npm test
+    - name: Test JS library code
+      run: npm test
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+    - name: Install dependencies
+      run: python -m pip install lark
+    - name: Test parser generator (Python)
+      run: python -m test.test

test/__init__.py

@@ -0,0 +1,21 @@
+?start: value
+
+?value: object
+      | array
+      | string
+      | SIGNED_NUMBER      -> number
+      | "true"             -> true
+      | "false"            -> false
+      | "null"             -> null
+
+array  : "[" [value ("," value)*] "]"
+object : "{" [pair ("," pair)*] "}"
+pair   : string ":" value
+
+string : ESCAPED_STRING
+
+%import common.ESCAPED_STRING
+%import common.SIGNED_NUMBER
+%import common.WS
+
+%ignore WS

test/json.lark

@@ -0,0 +1,72 @@
+from subprocess import Popen, PIPE
+
+from larkjs.__main__ import generate_js_standalone
+from lark import Lark
+
+TEST_CODE = r"""
+
+const parser = get_parser({transformer})
+
+console.log(JSON.stringify(parser.parse(input_text)))
+"""
+
+    
+class JsParser:
+    def __init__(self, lark_instance):
+        self.code = generate_js_standalone(lark_instance)
+
+    def parse(self, text, transformer=None):
+        js_code = self.code
+        js_code += 'const input_text = `' + text + '`;'
+        if transformer:
+            js_code += transformer
+        js_code += TEST_CODE
+
+        p = Popen(["node", "-"], stdin=PIPE, stdout=PIPE, stderr=PIPE)
+        stdout, stderr = p.communicate(js_code.encode())
+
+        if stderr:
+            raise ValueError(stderr.decode())
+        return stdout.decode()
+        
+    
+
+
+def test_json_parser():
+    parser = Lark.open('json.lark', rel_to=__file__, parser="lalr")
+    js_parser = JsParser(parser)
+
+    transformer = """
+    let transformer = {
+        number: ([n])  => parseFloat(n.value),
+        string: ([s])  => s.value.slice(1, -1),
+        array:  Array.from,
+        pair:   Array.from,
+        object: Object.fromEntries,
+
+        null: () => null,
+        true: () => true,
+        false: () => false,
+    }
+    """
+
+    text = r"""
+    {
+        "empty_object" : {},
+        "empty_array"  : [],
+        "booleans"     : { "YES" : true, "NO" : false },
+        "numbers"      : [ 0, 1, -2, 3.3, 4.4e5, 6.6e-7 ],
+        "strings"      : [ "This", [ "And" , "That", "And a \\"b" ] ],
+        "nothing"      : null
+    }
+    """
+    
+    res = js_parser.parse(text, transformer)
+    expected = r"""{"empty_object":{},"empty_array":[],"booleans":{"YES":true,"NO":false},"numbers":[0,1,-2,3.3,440000,6.6e-7],"strings":["This",["And","That","And a \\\"b"]],"nothing":null}"""
+    assert res.strip() == expected
+
+def test():
+    test_json_parser()
+
+if __name__ == '__main__':
+    test()