前言

近期在学习用airtest进行自动化测试，遇到的坑来记录一下。

问题

用pycharm学习airtest的时候发现任何poco的函数都会直接报错raise JSONDecodeError("Expecting value", s, err.value) from None异常，进行debug后发现问题出在minicap.py文件的get_display_info方法里面。
get_display_info代码

def get_display_info(self):

    display_info = self.adb.shell("%s -i" % self.CMD)
    display_info = json.loads(display_info)
    display_info["orientation"] = display_info["rotation"] / 90
    # 针对调整过手机分辨率的情况
    actual = self.adb.shell("dumpsys window displays")
    arr = re.findall(r'cur=(\d+)x(\d+)', actual)
    if len(arr) > 0:
        display_info['physical_width'] = display_info['width']
        display_info['physical_height'] = display_info['height']
        # 通过 adb shell dumpsys window displays | find "cur="
        # 获取到的分辨率是实际分辨率，但是需要的是非实际的
        if display_info["orientation"] in [1, 3]:
            display_info['width'] = int(arr[0][1])
            display_info['height'] = int(arr[0][0])
        else:
            display_info['width'] = int(arr[0][0])
            display_info['height'] = int(arr[0][1])
    return display_info

这个方法会被传一条命令进来 LD_LIBRARY_PATH=/data/local/tmp /data/local/tmp/minicap -i ; echo ---$?---

执行之后会返回这些

WARNING: linker: /data/local/tmp/minicap has text relocations. This is wasting memory and prevents security hardening. Please fix.

{

    "id": 0,

    "width": 540,

    "height": 960,

    "xdpi": 240.00,

    "ydpi": 240.00,

    "size": 4.59,

    "density": 1.50,

    "fps": 60.00,

    "secure": true,

    "rotation": 0

}

很明显里面多了一句警告，导致了**json.loads(display_info)**时候报错，下面我们改造一下这段代码。

添加如下两行

index = display_info.index("{")
display_info = display_info[index:len(display_info)]

最后代码如下

def get_display_info(self):
    display_info = self.adb.shell("%s -i" % self.CMD)
    index = display_info.index("{")
    display_info = display_info[index:len(display_info)]
    display_info = json.loads(display_info)
    display_info["orientation"] = display_info["rotation"] / 90
    # 针对调整过手机分辨率的情况
    actual = self.adb.shell("dumpsys window displays")
    arr = re.findall(r'cur=(\d+)x(\d+)', actual)
    if len(arr) > 0:
        display_info['physical_width'] = display_info['width']
        display_info['physical_height'] = display_info['height']
        # 通过 adb shell dumpsys window displays | find "cur="
        # 获取到的分辨率是实际分辨率，但是需要的是非实际的
        if display_info["orientation"] in [1, 3]:
            display_info['width'] = int(arr[0][1])
            display_info['height'] = int(arr[0][0])
        else:
            display_info['width'] = int(arr[0][0])
            display_info['height'] = int(arr[0][1])
    return display_info