feat: add guts for handling outputs and rendering them

src/output.rs

@@ -0,0 +1,33 @@
+use serde::Serialize;
+
+use crate::{CliError, CliResult};
+
+#[derive(Debug, Serialize)]
+struct ErrorBody<'a> {
+  pub code: i32,
+  pub message: &'a str,
+}
+
+#[derive(Debug, Serialize)]
+struct ErrorEnvelope<'a> {
+  pub error: ErrorBody<'a>,
+}
+
+pub fn render_json<T: Serialize>(value: &T, pretty: bool) -> CliResult<String> {
+  if pretty {
+    serde_json::to_string_pretty(value).map_err(|_| CliError::runtime("Failed to serialize output"))
+  } else {
+    serde_json::to_string(value).map_err(|_| CliError::runtime("Failed to serialize output"))
+  }
+}
+
+pub fn render_error(err: &CliError, pretty: bool) -> CliResult<String> {
+  let envelope = ErrorEnvelope {
+    error: ErrorBody {
+      code: err.code,
+      message: &err.message,
+    },
+  };
+
+  render_json(&envelope, pretty)
+}