feat: add defaultToPatchRelease option

Author: haydn

README.md

@@ -2,8 +2,8 @@
 > 
 > This is a fork of [semantic-release's
 > commit-analyzer](https://github.com/semantic-release/commit-analyzer) that has
-> been modified to include a `disableDefaultReleaseRules` option which can be
-> used like this:
+> been modified to include `disableDefaultReleaseRules` and
+> `defaultToPatchRelease` options which can be used like this:
 >
 > ```json
 > {
@@ -18,13 +18,14 @@
 >           { "type": "style", "release": "patch" }
 >         ],
 >         "disableDefaultReleaseRules": true,
+>         "defaultToPatchRelease": true,
 >       }
 >     ]
 >   ]
 > }
 > ```
 > 
-> This is heavily inspired by this pull-request and will not be needed once it is merged:
+> This is heavily inspired by this pull-request:
 > 
 > https://github.com/semantic-release/commit-analyzer/pull/211
 >

index.js

@@ -19,6 +19,7 @@ const debug = debugFactory("semantic-release:commit-analyzer");
  * @param {String} pluginConfig.config Requireable npm package with a custom conventional-changelog preset
  * @param {String|Array} pluginConfig.releaseRules A `String` to load an external module or an `Array` of rules.
  * @param {Boolean} pluginConfig.disableDefaultReleaseRules A `Boolean` that will prevent the default release rules to be used if a rule is not matched.
+ * @param {Boolean} pluginConfig.defaultToPatchRelease A `Boolean` to return a patch release when no release type is determined.
  * @param {Object} pluginConfig.parserOpts Additional `conventional-changelog-parser` options that will overwrite ones loaded by `preset` or `config`.
  * @param {Object} context The semantic-release context.
  * @param {Array<Object>} context.commits The commits to analyze.
@@ -86,5 +87,10 @@ export async function analyzeCommits(pluginConfig, context) {
 
   logger.log("Analysis of %s commits complete: %s release", commits.length, releaseType || "no");
 
+  if (releaseType === null && pluginConfig.defaultToPatchRelease === true) {
+    logger.log("No release type determined, defaulting to patch release");
+    return "patch";
+  }
+
   return releaseType;
 }