I tried this approach in 9.5.1 and it seems to work. Your final solution will need a bit of work to meet your specific requirements.
Steps:
- Create file with extension .dat ( 1 row containing words "Temp File" )
- Create a two step test case to read, manipulate, and store the data.
Step 1 - uses the Parse Text as Response step to read the file and store the contents in a property "fl_myFile". I added a scriptable assertion that places fl_myFile in a local variable, adds the string "\r\n Added new row" and set the string back into fl_myFile and returns true so as not to trip the assertion into failing the test case.
Step 2 - uses a Do Nothing step and I placed a Save Property Value to File filter on the step. I filtered in "fl_myFile" and added the location as the same location and file name as the file read in the Parse Text as Response step.
If I do not check the Append Mode option, the file is overwritten with the content in fl_myFile. If I check the Append Mode, the content is appended to the bottom of the file.
Sample Data:
Test Case:
Step 1: Read Input File Location same as Save Property to File location:
Step 1: Scripted assertion adds content to property:
Step 2: Save Property to File:
Result (Append Mode Unchecked causes full replacement):
Result (Append Mode Checked appends content in property to end of file):
Notice, that the test case is appending the entire amount of content to the file; hence there are two Temp File Created and two Added new row lines. Add a bit of custom logic to update data in place or add new data as desired.