fix(version): should not throw when changelog.md is missing

packages/core/src/conventional-commits/read-existing-changelog.ts

@@ -11,15 +11,24 @@ import { BLANK_LINE, COMMIT_GUIDELINE } from './constants';
 export async function readExistingChangelog(pkg) {
   const changelogFileLoc = path.join(pkg.location, 'CHANGELOG.md');
 
+  let chain: Promise<any> = Promise.resolve();
+
   // catch allows missing file to pass without breaking chain
-  let changelogContents = await fs.readFile(changelogFileLoc, 'utf8');
+  chain = chain.then(() => fs.readFile(changelogFileLoc, 'utf8').catch(() => ''));
+
+  chain = chain.then((changelogContents) => {
+    // Remove the header if it exists, thus starting at the first entry.
+    const headerIndex = changelogContents.indexOf(COMMIT_GUIDELINE);
+
+    if (headerIndex !== -1) {
+      return changelogContents.substring(headerIndex + COMMIT_GUIDELINE.length + BLANK_LINE.length);
+    }
 
-  // Remove the header if it exists, thus starting at the first entry.
-  const headerIndex = changelogContents.indexOf(COMMIT_GUIDELINE);
+    return changelogContents;
+  });
 
-  if (headerIndex !== -1) {
-    changelogContents = changelogContents.substring(headerIndex + COMMIT_GUIDELINE.length + BLANK_LINE.length);
-  }
+  // consumer expects resolved tuple
+  chain = chain.then((changelogContents) => [changelogFileLoc, changelogContents]);
 
-  return [changelogFileLoc, changelogContents];
+  return chain;
 }