Implement reset_stdio_counter()

Author: JamesWrigley

docs/src/_changelog.md

@@ -9,6 +9,10 @@ Changelog](https://keepachangelog.com).
 
 ## Unreleased
 
+### Added
+- Implemented [`reset_stdio_count()`](@ref) to provide a public API for
+  resetting the stdio count ([#1172]).
+
 ### Changed
 - IJulia was completely refactored to minimize global state ([#1172]). This
   allows for better testing (for the first time we can test kernel execution)

docs/src/library/public.md

@@ -45,4 +45,5 @@ IJulia.load_string
 ```@docs
 IJulia.readprompt
 IJulia.set_max_stdio
+IJulia.reset_stdio_count
 ```

src/IJulia.jl

@@ -485,6 +485,15 @@ function set_max_stdio(max_output::Integer; kernel)
     kernel.max_output_per_request[] = max_output
 end
 
+"""
+    reset_stdio_count()
+
+Reset the count of the number of bytes written to stdout/stderr. See
+[`set_max_stdio`](@ref) for more details.
+"""
+function reset_stdio_count(kernel=_default_kernel)
+    kernel.stdio_bytes = 0
+end
 
 #######################################################################
 

test/stdio.jl

@@ -39,4 +39,7 @@ using IJulia
         end
     end
 
+    kernel.stdio_bytes = 42
+    IJulia.reset_stdio_count(kernel)
+    @test kernel.stdio_bytes == 0
 end