Struct RenderHarness 

pub struct RenderHarness { /* private fields */ }

Test harness for capturing rendered output.

Provides utilities for rendering components to a test buffer and converting the output to strings for snapshot testing.

Example

use tui_dispatch::testing::RenderHarness;

let mut render = RenderHarness::new(80, 24);

// Render a component
let output = render.render_to_string(|frame| {
    my_component.render(frame, frame.area(), props);
});

// Use with insta for snapshot testing
insta::assert_snapshot!(output);

Implementations

impl RenderHarness

pub fn new(width: u16, height: u16) -> Self

Create a new render harness with the specified dimensions.

pub fn render<F>(&mut self, render_fn: F) -> &Buffer

where F: FnOnce(&mut Frame<'_>),

Render using the provided function and return the buffer.

pub fn render_to_string<F>(&mut self, render_fn: F) -> String

where F: FnOnce(&mut Frame<'_>),

Render and convert the buffer to a string representation.

The output includes ANSI escape codes for colors and styles.

pub fn render_to_string_plain<F>(&mut self, render_fn: F) -> String

where F: FnOnce(&mut Frame<'_>),

Render and convert to a plain string (no ANSI codes).

Useful for simple text assertions without style information.

pub fn size(&self) -> (u16, u16)

Get the current terminal size.

pub fn resize(&mut self, width: u16, height: u16)

Resize the terminal.