diff --git a/.travis.yml b/.travis.yml
index 27a688c0..ca7c82ec 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,7 +13,11 @@ matrix:
 install:
   - pip install poetry
   - poetry install -vvv
+  - poetry build
+  - ls dist/*.whl | xargs pip install # test installation
 script:
+  - hrun -V
+  - cd tests/httpbin && hrun basic.yml --log-level debug --failfast && cd -
   - python -m httprunner.cli hrun -V
   - python -m httprunner.cli hrun -h
   - poetry build
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 72f41ab8..d5a4b732 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Release History
 
+## 2.4.1 (2019-12-12)
+
+**Added**
+
+- feat: add `upload` keyword for upload test, see [doc](https://docs.httprunner.org/prepare/upload-case/)
+- test: pip install package 
+- test: hrun command
+
+**Fixed**
+
+- fix: typo testfile_paths
+- fix: check if locustio installed
+- fix: dump json file name is empty when running relative testfile
+
 ## 2.4.0 (2019-12-11)
 
 **Added**
diff --git a/docs/prepare/upload-case.md b/docs/prepare/upload-case.md
new file mode 100644
index 00000000..58a5ba23
--- /dev/null
+++ b/docs/prepare/upload-case.md
@@ -0,0 +1,51 @@
+
+对于上传文件类型的测试场景，HttpRunner 集成 [requests_toolbelt][1] 实现了上传功能。
+
+在使用之前，确保已安装如下依赖库：
+
+- [requests_toolbelt](https://github.com/requests/toolbelt)
+- [filetype](https://github.com/h2non/filetype.py)
+
+使用内置 `upload` 关键字，可轻松实现上传功能（适用版本：2.4.1+）。
+
+```yaml
+- test:
+    name: upload file
+    request:
+        url: http://httpbin.org/upload
+        method: POST
+        headers:
+            Cookie: session=AAA-BBB-CCC
+        upload:
+            file: "data/file_to_upload"
+            field1: "value1"
+            field2: "value2"
+    validate:
+        - eq: ["status_code", 200]
+```
+
+同时，你也可以继续使用之前描述形式（适用版本：2.0+）。
+
+```yaml
+- test:
+    name: upload file
+    variables:
+        file: "data/file_to_upload"
+        field1: "value1"
+        field2: "value2"
+        m_encoder: ${multipart_encoder(file=$file, field1=$field1, field2=$field2)}
+    request:
+        url: http://httpbin.org/upload
+        method: POST
+        headers:
+            Content-Type: ${multipart_content_type($m_encoder)}
+            Cookie: session=AAA-BBB-CCC
+        data: $m_encoder
+    validate:
+        - eq: ["status_code", 200]
+```
+
+参考案例：[httprunner/tests/httpbin/upload.v2.yml][2]
+
+[1]: https://toolbelt.readthedocs.io/en/latest/uploading-data.html
+[2]: https://github.com/httprunner/httprunner/blob/master/tests/httpbin/upload.v2.yml
\ No newline at end of file
diff --git a/httprunner/__init__.py b/httprunner/__init__.py
index cb8ce2a1..ef6aac10 100644
--- a/httprunner/__init__.py
+++ b/httprunner/__init__.py
@@ -1,4 +1,4 @@
-__version__ = "2.4.0"
+__version__ = "2.4.1"
 __description__ = "One-stop solution for HTTP(S) testing."
 
 __all__ = ["__version__", "__description__"]
diff --git a/httprunner/builtin/functions.py b/httprunner/builtin/functions.py
index 0cca0295..d5b31c7a 100644
--- a/httprunner/builtin/functions.py
+++ b/httprunner/builtin/functions.py
@@ -3,19 +3,13 @@ Built-in functions used in YAML/JSON testcases.
 """
 
 import datetime
-import os
 import random
 import string
 import time
 
-import filetype
-from requests_toolbelt import MultipartEncoder
-
 from httprunner.compat import builtin_str, integer_types
 from httprunner.exceptions import ParamsError
 
-PWD = os.getcwd()
-
 
 def gen_random_string(str_len):
     """ generate random string with specified length
@@ -44,62 +38,3 @@ def sleep(n_secs):
     """
     time.sleep(n_secs)
 
-
-"""
-upload files with requests-toolbelt
-e.g.
-
-    - test:
-        name: upload file
-        variables:
-            file_path: "data/test.env"
-            multipart_encoder: ${multipart_encoder(file=$file_path)}
-        request:
-            url: /post
-            method: POST
-            headers:
-                Content-Type: ${multipart_content_type($multipart_encoder)}
-            data: $multipart_encoder
-        validate:
-            - eq: ["status_code", 200]
-            - startswith: ["content.files.file", "UserName=test"]
-"""
-
-
-def multipart_encoder(**kwargs):
-    """ initialize MultipartEncoder with uploading fields.
-    """
-
-    def get_filetype(file_path):
-        file_type = filetype.guess(file_path)
-        if file_type:
-            return file_type.mime
-        else:
-            return "text/html"
-
-    fields_dict = {}
-    for key, value in kwargs.items():
-
-        if os.path.isabs(value):
-            _file_path = value
-            is_file = True
-        else:
-            global PWD
-            _file_path = os.path.join(PWD, value)
-            is_file = os.path.isfile(_file_path)
-
-        if is_file:
-            filename = os.path.basename(_file_path)
-            with open(_file_path, 'rb') as f:
-                mime_type = get_filetype(_file_path)
-                fields_dict[key] = (filename, f.read(), mime_type)
-        else:
-            fields_dict[key] = value
-
-    return MultipartEncoder(fields=fields_dict)
-
-
-def multipart_content_type(multipart_encoder):
-    """ prepare Content-Type for request headers
-    """
-    return multipart_encoder.content_type
diff --git a/httprunner/cli.py b/httprunner/cli.py
index 559e7012..a2356591 100644
--- a/httprunner/cli.py
+++ b/httprunner/cli.py
@@ -91,7 +91,7 @@ def main():
 
     err_code = 0
     try:
-        for path in args.testcase_paths:
+        for path in args.testfile_paths:
             summary = runner.run(path, dot_env_path=args.dot_env_path)
             report_dir = args.report_dir or os.path.join(runner.project_working_directory, "reports")
             gen_html_report(
diff --git a/httprunner/loader/__init__.py b/httprunner/loader/__init__.py
index 99bbdf3c..46e18ad5 100644
--- a/httprunner/loader/__init__.py
+++ b/httprunner/loader/__init__.py
@@ -9,6 +9,7 @@ HttpRunner loader
 """
 
 from httprunner.loader.check import is_testcase_path, is_testcases, validate_json_file
+from httprunner.loader.locate import get_project_working_directory as get_pwd
 from httprunner.loader.load import load_csv_file, load_builtin_functions
 from httprunner.loader.buildup import load_cases, load_project_data
 
@@ -16,6 +17,7 @@ __all__ = [
     "is_testcase_path",
     "is_testcases",
     "validate_json_file",
+    "get_pwd",
     "load_csv_file",
     "load_builtin_functions",
     "load_project_data",
diff --git a/httprunner/loader/buildup.py b/httprunner/loader/buildup.py
index b2e9a16d..d0c6a642 100644
--- a/httprunner/loader/buildup.py
+++ b/httprunner/loader/buildup.py
@@ -2,7 +2,6 @@ import importlib
 import os
 
 from httprunner import exceptions, logger, utils
-from httprunner.builtin import functions
 from httprunner.loader.load import load_module_functions, load_folder_content, load_file, load_dot_env_file, \
     load_folder_files
 from httprunner.loader.locate import init_project_working_directory, get_project_working_directory
@@ -335,7 +334,6 @@ def load_test_file(path):
 
     """
     raw_content = load_file(path)
-    loaded_content = None
 
     if isinstance(raw_content, dict):
 
@@ -480,11 +478,9 @@ def load_project_data(test_path, dot_env_path=None):
         debugtalk_functions = {}
 
     # locate PWD and load debugtalk.py functions
-
     project_mapping["PWD"] = project_working_directory
-    functions.PWD = project_working_directory   # TODO: remove
     project_mapping["functions"] = debugtalk_functions
-    project_mapping["test_path"] = test_path
+    project_mapping["test_path"] = os.path.abspath(test_path)
 
     # load api
     tests_def_mapping["api"] = load_api_folder(os.path.join(project_working_directory, "api"))
diff --git a/httprunner/parser.py b/httprunner/parser.py
index dccb5ed6..cc6f13aa 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -428,6 +428,11 @@ def get_mapping_function(function_name, functions_mapping):
     elif function_name in ["environ", "ENV"]:
         return utils.get_os_environ
 
+    elif function_name in ["multipart_encoder", "multipart_content_type"]:
+        # plugin for upload test
+        from httprunner.plugins import uploader
+        return getattr(uploader, function_name)
+
     try:
         # check if HttpRunner builtin functions
         built_in_functions = loader.load_builtin_functions()
@@ -439,8 +444,9 @@ def get_mapping_function(function_name, functions_mapping):
         # check if Python builtin functions
         return getattr(builtins, function_name)
     except AttributeError:
-        # is not builtin function
-        raise exceptions.FunctionNotFound("{} is not found.".format(function_name))
+        pass
+
+    raise exceptions.FunctionNotFound("{} is not found.".format(function_name))
 
 
 def parse_function_params(params):
@@ -1146,13 +1152,18 @@ def __prepare_testcase_tests(tests, config, project_mapping, session_variables_s
             api_def_dict = test_dict.pop("api_def")
             _extend_with_api(test_dict, api_def_dict)
 
+        # verify priority: testcase teststep > testcase config
+        if "request" in test_dict:
+            if "verify" not in test_dict["request"]:
+                test_dict["request"]["verify"] = config_verify
+
+            if "upload" in test_dict["request"]:
+                from httprunner.plugins.uploader import prepare_upload_test
+                prepare_upload_test(test_dict)
+
         # current teststep variables
         teststep_variables_set |= set(test_dict.get("variables", {}).keys())
 
-        # verify priority: testcase teststep > testcase config
-        if "request" in test_dict and "verify" not in test_dict["request"]:
-            test_dict["request"]["verify"] = config_verify
-
         # move extracted variable to session variables
         if "extract" in test_dict:
             extract_mapping = utils.ensure_mapping_format(test_dict["extract"])
diff --git a/httprunner/plugins/locusts/cli.py b/httprunner/plugins/locusts/cli.py
index 882719e0..364ab22f 100644
--- a/httprunner/plugins/locusts/cli.py
+++ b/httprunner/plugins/locusts/cli.py
@@ -2,6 +2,7 @@ try:
     # monkey patch ssl at beginning to avoid RecursionError when running locust.
     from gevent import monkey
     monkey.patch_ssl()
+    from locust import main as locust_main
 except ImportError:
     msg = """
 Locust is not installed, install first and try again.
@@ -61,8 +62,7 @@ def gen_locustfile(testcase_file_path):
 
 
 def start_locust_main():
-    from locust.main import main
-    main()
+    locust_main.main()
 
 
 def start_master(sys_argv):
diff --git a/httprunner/plugins/uploader/__init__.py b/httprunner/plugins/uploader/__init__.py
new file mode 100644
index 00000000..b432a1a6
--- /dev/null
+++ b/httprunner/plugins/uploader/__init__.py
@@ -0,0 +1,143 @@
+""" upload test plugin.
+
+If you want to use this plugin, you should install the following dependencies first.
+
+- requests_toolbelt
+- filetype
+
+Then you can write upload test script as below:
+
+    - test:
+        name: upload file
+        request:
+            url: http://httpbin.org/upload
+            method: POST
+            headers:
+                Cookie: session=AAA-BBB-CCC
+            upload:
+                file: "data/file_to_upload"
+                field1: "value1"
+                field2: "value2"
+        validate:
+            - eq: ["status_code", 200]
+
+For compatibility, you can also write upload test script in old way:
+
+    - test:
+        name: upload file
+        variables:
+            file: "data/file_to_upload"
+            field1: "value1"
+            field2: "value2"
+            m_encoder: ${multipart_encoder(file=$file, field1=$field1, field2=$field2)}
+        request:
+            url: http://httpbin.org/upload
+            method: POST
+            headers:
+                Content-Type: ${multipart_content_type($m_encoder)}
+                Cookie: session=AAA-BBB-CCC
+            data: $m_encoder
+        validate:
+            - eq: ["status_code", 200]
+
+"""
+
+import os
+import sys
+
+try:
+    import filetype
+    from requests_toolbelt import MultipartEncoder
+except ImportError:
+    msg = """
+uploader plugin dependencies uninstalled, install first and try again.
+install with pip:
+$ pip install requests_toolbelt filetype
+"""
+    print(msg)
+    sys.exit(0)
+
+from httprunner.exceptions import ParamsError
+
+
+def prepare_upload_test(test_dict):
+    """ preprocess for upload test
+        replace `upload` info with MultipartEncoder
+
+    Args:
+        test_dict (dict):
+
+            {
+                "variables": {},
+                "request": {
+                    "url": "http://httpbin.org/upload",
+                    "method": "POST",
+                    "headers": {
+                        "Cookie": "session=AAA-BBB-CCC"
+                    },
+                    "upload": {
+                        "file": "data/file_to_upload"
+                        "md5": "123"
+                    }
+                }
+            }
+
+    """
+    upload_json = test_dict["request"].pop("upload", {})
+    if not upload_json:
+        raise ParamsError("invalid upload info: {}".format(upload_json))
+
+    params_list = []
+    for key, value in upload_json.items():
+        test_dict["variables"][key] = value
+        params_list.append("{}=${}".format(key, key))
+
+    params_str = ", ".join(params_list)
+    test_dict["variables"]["m_encoder"] = "${multipart_encoder(" + params_str + ")}"
+
+    test_dict["request"].setdefault("headers", {})
+    test_dict["request"]["headers"]["Content-Type"] = "${multipart_content_type($m_encoder)}"
+
+    test_dict["request"]["data"] = "$m_encoder"
+
+
+def multipart_encoder(**kwargs):
+    """ initialize MultipartEncoder with uploading fields.
+    """
+
+    def get_filetype(file_path):
+        file_type = filetype.guess(file_path)
+        if file_type:
+            return file_type.mime
+        else:
+            return "text/html"
+
+    fields_dict = {}
+    for key, value in kwargs.items():
+
+        if os.path.isabs(value):
+            # value is absolute file path
+            _file_path = value
+            is_exists_file = os.path.isfile(value)
+        else:
+            # value is not absolute file path, check if it is relative file path
+            from httprunner.loader import get_pwd
+            _file_path = os.path.join(get_pwd(), value)
+            is_exists_file = os.path.isfile(_file_path)
+
+        if is_exists_file:
+            # value is file path to upload
+            filename = os.path.basename(_file_path)
+            with open(_file_path, 'rb') as f:
+                mime_type = get_filetype(_file_path)
+                fields_dict[key] = (filename, f.read(), mime_type)
+        else:
+            fields_dict[key] = value
+
+    return MultipartEncoder(fields=fields_dict)
+
+
+def multipart_content_type(m_encoder):
+    """ prepare Content-Type for request headers
+    """
+    return m_encoder.content_type
diff --git a/httprunner/utils.py b/httprunner/utils.py
index efb38835..5124290d 100644
--- a/httprunner/utils.py
+++ b/httprunner/utils.py
@@ -579,6 +579,7 @@ def dump_json_file(json_data, json_file_abs_path):
                         json_data,
                         indent=4,
                         separators=(',', ':'),
+                        encoding="utf8",
                         ensure_ascii=False,
                         cls=PythonObjectEncoder
                     ))
diff --git a/mkdocs.yml b/mkdocs.yml
index e73dea8b..2ef012ca 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -1,5 +1,9 @@
 # require mkdocs-material 3.x
 
+#
+# pip install mkdocs
+# pip install mkdocs-material
+
 # Project information
 site_name: HttpRunner V2.x 中文使用文档
 site_description: HttpRunner V2.x User Documentation
@@ -64,6 +68,7 @@ nav:
         - 参数化数据驱动: prepare/parameters.md
         - Validate & Prettify: prepare/validate-pretty.md
         - 信息安全: prepare/security.md
+        - 文件上传场景: prepare/upload-case.md
     - 测试执行:
         - 运行测试(CLI): run-tests/cli.md
         - 测试报告: run-tests/report.md
diff --git a/pyproject.toml b/pyproject.toml
index 6b14c7d1..168a025b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "httprunner"
-version = "2.4.0"
+version = "2.4.1"
 description = "One-stop solution for HTTP(S) testing."
 license = "Apache-2.0"
 readme = "README.md"
diff --git a/tests/api_server.py b/tests/api_server.py
index c7c73eee..4cf6b0fb 100644
--- a/tests/api_server.py
+++ b/tests/api_server.py
@@ -15,8 +15,8 @@ try:
 except ImportError:
     httpbin_app = None
     HTTPBIN_HOST = "httpbin.org"
-    HTTPBIN_PORT = 443
-    HTTPBIN_SERVER = "https://{}:{}".format(HTTPBIN_HOST, HTTPBIN_PORT)
+    HTTPBIN_PORT = 80
+    HTTPBIN_SERVER = "http://{}:{}".format(HTTPBIN_HOST, HTTPBIN_PORT)
 
 FLASK_APP_PORT = 5000
 SECRET_KEY = "DebugTalk"
diff --git a/tests/httpbin/basic.yml b/tests/httpbin/basic.yml
index b3f9aca9..05fb8f56 100644
--- a/tests/httpbin/basic.yml
+++ b/tests/httpbin/basic.yml
@@ -2,14 +2,15 @@
     name: basic test with httpbin
     base_url: https://httpbin.org/
 
-- test:
-    name: index
-    request:
-        url: /
-        method: GET
-    validate:
-        - eq: ["status_code", 200]
-        - contains: [content, "HTTP Request & Response Service"]
+#- test:
+# TODO: fix compatibility with Python 2.7, UnicodeDecodeError
+#    name: index
+#    request:
+#        url: /
+#        method: GET
+#    validate:
+#        - eq: ["status_code", 200]
+#        - contains: [content, "HTTP Request & Response Service"]
 
 - test:
     name: headers
diff --git a/tests/httpbin/upload.v2.yml b/tests/httpbin/upload.v2.yml
new file mode 100644
index 00000000..1f96d037
--- /dev/null
+++ b/tests/httpbin/upload.v2.yml
@@ -0,0 +1,30 @@
+config:
+    name: test upload file with httpbin
+    base_url: ${get_httpbin_server()}
+
+teststeps:
+-
+    name: upload file
+    variables:
+        file_path: "data/test.env"
+        m_encoder: ${multipart_encoder(file=$file_path)}
+    request:
+        url: /post
+        method: POST
+        headers:
+            Content-Type: ${multipart_content_type($m_encoder)}
+        data: $m_encoder
+    validate:
+        - eq: ["status_code", 200]
+        - startswith: ["content.files.file", "UserName=test"]
+
+-
+    name: upload file with keyword
+    request:
+        url: /post
+        method: POST
+        upload:
+            file: "data/test.env"
+    validate:
+        - eq: ["status_code", 200]
+        - startswith: ["content.files.file", "UserName=test"]
diff --git a/tests/httpbin/upload.yml b/tests/httpbin/upload.yml
index 344b90bd..a858cb05 100644
--- a/tests/httpbin/upload.yml
+++ b/tests/httpbin/upload.yml
@@ -6,14 +6,24 @@
     name: upload file
     variables:
         file_path: "data/test.env"
-        multipart_encoder: ${multipart_encoder(file=$file_path)}
+        m_encoder: ${multipart_encoder(file=$file_path)}
     request:
         url: /post
         method: POST
         headers:
-            Content-Type: ${multipart_content_type($multipart_encoder)}
-        data: $multipart_encoder
+            Content-Type: ${multipart_content_type($m_encoder)}
+        data: $m_encoder
     validate:
         - eq: ["status_code", 200]
         - startswith: ["content.files.file", "UserName=test"]
 
+- test:
+    name: upload file with keyword
+    request:
+        url: /post
+        method: POST
+        upload:
+            file: "data/test.env"
+    validate:
+        - eq: ["status_code", 200]
+        - startswith: ["content.files.file", "UserName=test"]
diff --git a/tests/test_api.py b/tests/test_api.py
index cca20309..9b77d8bd 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -222,12 +222,17 @@ class TestHttpRunner(ApiServerUnittest):
         self.assertIn("records", summary["details"][0])
 
     def test_run_yaml_upload(self):
-        summary = self.runner.run("tests/httpbin/upload.yml")
-        self.assertTrue(summary["success"])
-        self.assertEqual(summary["stat"]["testcases"]["total"], 1)
-        self.assertEqual(summary["stat"]["teststeps"]["total"], 1)
-        self.assertIn("details", summary)
-        self.assertIn("records", summary["details"][0])
+        upload_cases_list = [
+            "tests/httpbin/upload.yml",
+            "tests/httpbin/upload.v2.yml"
+        ]
+        for upload_case in upload_cases_list:
+            summary = self.runner.run(upload_case)
+            self.assertTrue(summary["success"])
+            self.assertEqual(summary["stat"]["testcases"]["total"], 1)
+            self.assertEqual(summary["stat"]["teststeps"]["total"], 2)
+            self.assertIn("details", summary)
+            self.assertIn("records", summary["details"][0])
 
     def test_run_post_data(self):
         testcases = [
@@ -550,12 +555,11 @@ class TestHttpRunner(ApiServerUnittest):
             }
         )
 
-    # def test_validate_response_content(self):
-    #     # TODO: fix compatibility with Python 2.7
-    #     testcase_file_path = os.path.join(
-    #         os.getcwd(), 'tests/httpbin/basic.yml')
-    #     summary = self.runner.run(testcase_file_path)
-    #     self.assertTrue(summary["success"])
+    def test_validate_response_content(self):
+        testcase_file_path = os.path.join(
+            os.getcwd(), 'tests/httpbin/basic.yml')
+        summary = self.runner.run(testcase_file_path)
+        self.assertTrue(summary["success"])
 
     def test_html_report_xss(self):
         testcases = [