Charles: four ways to modify the input parameters or return results of the interface

Preface ：

charles It is a commonly used packet capturing tool in development , It's very powerful , Among them, those who can directly modify the request are 4 Methods , Namely ：map Local、map Remote、Rewrite and Breakpoints.

One 、 map Local   

1. effect

Will match url Map to local file

2. Applicable scenario

（1） You need to constantly modify the returned results of the interface to test various case

（2） When the back end of a requested return result is difficult to simulate

3. step

（1） Save the response result of the request ： Right click on the request  save Response, Save the original message locally

（2） Map the request to the file ： Right click on the request Map local

Map the request to your local file

 （3） According to the demand , Modify the local file and save , When the interface is requested again , You will see that the returned result has been changed to the local file we mapped

Two 、 map Remote 

1. effect

Remote mapping , That is, map the domain name you want to request to another remote domain name . Usually used to switch environments ,

2. Applicable scenario

（1） Switch the interface of the test environment to the online environment

（2） Protocol conversion , If you put https become http

3. step

（1） After selecting the request , Right click on the Map Remote

（2） Modify the mapping address information according to the situation

（3） Refresh the page and re request , You will find that the request has been mapped to the modified new address

3、 ... and 、 Rewrite 

1. effect

For matching url, Regular substitution request or response All kinds of values , Include header、host、url、path、query param、response status、body

2. Applicable scenario

（1） Modify the input parameters of the request 、header Medium parameters and other scenarios

3. step

（1） Click on Tools → Click on Rewrite

（2） Check Enable Rewrite, Click on add, Add the request that needs to be rewritten url Information

（3） Click on the bottom right corner add Add fields that need to be rewritten

 

（4） Refresh the page and re request , You will find that the modified field has been rewritten

Four 、 Breakpoints

1. effect

Yes url Breaking point , Interrupts Request or Response, When pausing, you can modify the request data or response results

2. Applicable scenario

（1） Every request needs to be modified Request or Response Of header、 Enter the reference 、 Return partial values of results, etc

3. step

（1） Right click on the request Breakpoints, That is, open the breakpoint （ The default is Request and Response, Can be found in Breakpoint Settings Revision in China ）

（2） Breakpoints can be modified Request or Response Value

（3） Click Execute, After continuing to execute, you can see that the modification takes effect