message: feat(changelog): explicitly fail when there is no reportable change
diff: @@ -145,14 +145,14 @@ async function main() {
  others,
  } = diffTypes(previous, current);
  - const output = [writeAddedRemoved(added, removed)];
  + const outputs = [writeAddedRemoved(added, removed)];
  if (modified.size) {
  const modifiedOutput = [`## Modified\n`];
  for (const [key, value] of modified.entries()) {
  modifiedOutput.push(`* ${key}`);
  modifiedOutput.push(writeAddedRemovedInline(value.added, value.removed));
  }
  - output.push(modifiedOutput.join("\n"));
  + outputs.push(modifiedOutput.join("\n"));
  }
  if (others.modified.size) {
  @@ -161,9 +161,15 @@ async function main() {
  modifiedOutput.push(`* ${key}`);
  modifiedOutput.push(writeAddedRemovedInline(value.added, value.removed));
  }
  - output.push(modifiedOutput.join("\n"));
  + outputs.push(modifiedOutput.join("\n"));
  + }
  +
  + const output = outputs.join("\n\n");
  + if (output.length) {
  + console.log(output);
  + } else {
  + throw new Error(`No change reported between ${base} and ${head}.`);
  }
  - console.log(output.join("\n\n"));
  }
  await main();
  