examples/components/reverser/README.md

# Reverser Component

This component provides a service that reverses strings. It explores
structured configuration to conditionally modify behavior, as well as
optional downstream component dependencies for replacement logic.
It is primarily used to demonstrate dynamic configurations and test
mocking capabilities in Fuchsia.

## Structured Configuration

This component uses Structured Configuration to conditionally alter
its behavior at runtime. You can think of these config values as
analogous to command-line arguments or function parameters, provided
by the runner environment when the component starts.

### `switch_case`
- **Type**: `bool`
- **Description**: When set to `true`, the component will invert the
  alphabetical case of all characters in the string *in addition* to
  reversing the string order. When `false`, it only reverses the
  string.
- **Example Use Case**:
  - `switch_case: false` -> `"Hello Fuchsia!"` becomes `"!aishcuF olleH"`
  - `switch_case: true`  -> `"Hello Fuchsia!"` becomes `"!AISHCUf OLLEh"`

### `use_replacer`
- **Type**: `bool`
- **Description**: When set to `true`, the component will attempt to
  connect to the optional `fuchsia.examples.reverser.Replacer`
  protocol and filter the string through it *before* performing the
  reversal and case-switching logic. If `false` or the protocol is
  unavailable, no replacement occurs.
- **Example Use Case**:
  - Assuming the `Replacer` changes `"Fuchsia"` to `"Zircon"`:
  - `use_replacer: true, switch_case: false` -> `"Hello Fuchsia!"` evaluates `"Hello Zircon!"` and returns `"!nocriZ olleH"`