From e77905dbcad2e6e1c1d9014ae093d2006b5aa738 Mon Sep 17 00:00:00 2001
From: Davi Kawasaki <davishinjik@gmail.com>
Date: Sun, 7 Mar 2021 10:08:27 -0300
Subject: [PATCH] feat: provide ignore packages CLI directive

---
 .gitignore                                    |   2 +-
 README.md                                     |  37 +++++
 bin/cli.js                                    |  12 +-
 bin/runner.js                                 |   2 +-
 lib/createInlinePluginCreator.js              |   1 +
 lib/getWorkspacesYarn.js                      |  10 +-
 lib/git.js                                    |  30 ++++
 lib/glob.js                                   |   9 +-
 lib/updateDeps.js                             | 147 +++++++++++++++++-
 lib/utils.js                                  |  60 +++++++
 package.json                                  |   2 +-
 test/bin/cli.test.js                          |  16 ++
 .../yarnWorkspacesIgnore/package.json         |  21 +++
 .../packages/a/package.json                   |   8 +
 .../packages/b/package.json                   |  12 ++
 .../packages/c/.releaserc.json                |   3 +
 .../packages/c/package.json                   |   8 +
 .../packages/d/package.json                   |   4 +
 .../yarnWorkspacesIgnoreSplit/package.json    |  23 +++
 .../packages/a/package.json                   |   8 +
 .../packages/b/package.json                   |  11 ++
 .../packages/c/.releaserc.json                |   3 +
 .../packages/c/package.json                   |   8 +
 .../packages/d/package.json                   |   4 +
 test/lib/getWorkspacesYarn.test.js            |  46 ++++--
 test/lib/git.test.js                          |  90 +++++++++++
 test/lib/multiSemanticRelease.test.js         |  94 ++++++++++-
 test/lib/updateDeps.test.js                   | 106 +++++++++++--
 test/lib/utils.test.js                        |  69 ++++++++
 yarn.lock                                     |  42 ++---
 30 files changed, 817 insertions(+), 71 deletions(-)
 create mode 100644 lib/git.js
 create mode 100644 lib/utils.js
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/packages/a/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/packages/b/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/packages/c/.releaserc.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/packages/c/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnore/packages/d/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/packages/a/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/packages/b/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/.releaserc.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/package.json
 create mode 100644 test/fixtures/yarnWorkspacesIgnoreSplit/packages/d/package.json
 create mode 100644 test/lib/git.test.js
 create mode 100644 test/lib/utils.test.js

diff --git a/.gitignore b/.gitignore
index 5793926..2cf3958 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
-/node_modules/
+**/node_modules/**
 /coverage/
 *.log
diff --git a/README.md b/README.md
index b08edc1..35f2067 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,32 @@ _But_ in multi-semantic-release this configuration can be done globally (in your
 
 multi-semantic-release does not support any command line arguments (this wasn't possible without duplicating files from semantic-release, which I've tried to avoid).
 
+Make sure to have a `workspaces` attribute inside your `package.json` project file. In there, you can set a list of packages that you might want to process in the msr process, as well as ignore others. For example, let's say your project has 4 packages (i.e. a, b, c and d) and you want to process only a and d (ignore b and c). You can set the following structure in your `package.json` file:
+```json
+{
+	"name": "msr-test-yarn",
+	"author": "Dave Houlbrooke <dave@shax.com",
+	"version": "0.0.0-semantically-released",
+	"private": true,
+	"license": "0BSD",
+	"engines": {
+		"node": ">=8.3"
+	},
+	"workspaces": [
+      "packages/*",
+      "!packages/b/**",
+      "!packages/c/**"
+	],
+	"release": {
+		"plugins": [
+			"@semantic-release/commit-analyzer",
+			"@semantic-release/release-notes-generator"
+		],
+		"noCi": true
+	}
+}
+```
+
 ## CLI
 There are several tweaks to adapt **msr** to some corner cases:
 
@@ -43,6 +69,17 @@ There are several tweaks to adapt **msr** to some corner cases:
 |`--deps.bump`|string| Define deps version update rule. `override` — replace any prev version with the next one, `satisfy` — check the next pkg version against its current references. If it matches (`*` matches to any, `1.1.0` matches `1.1.x`, `1.5.0` matches to `^1.0.0` and so on) release will not be triggered, if not `override` strategy will be applied instead; `inherit` will try to follow the current declaration version/range. `~1.0.0` + `minor` turns into `~1.1.0`, `1.x` + `major` gives `2.x`, but `1.x` + `minor` gives `1.x` so there will be no release, etc. +  **Experimental feat**  | `override`
 |`--deps.release`|string| Define release type for dependent package if any of its deps changes. `patch`, `minor`, `major` — strictly declare the release type that occurs when any dependency is updated; `inherit` — applies the "highest" release of updated deps to the package. For example, if any dep has a breaking change, `major` release will be applied to the all dependants up the chain. **Experimental feat** | `patch`
 |`--dry-run`|bool |Dry run mode| `false`
+|`--ignore-packages`|string|Packages list to be ignored on bumping process (append to the ones that already exist at package.json workspaces)|`null`
+
+Examples:
+
+```
+$ multi-semantic-release --debug
+$ multi-semantic-release --deps.bump=satisfy --deps.release=patch
+$ multi-semantic-release --ignore-packages=packages/a/**,packages/b/**
+```
+
+You can also combine the CLI `--ignore-packages` options with the `!` operator at each package inside `package.json.workspaces` attribute. Even though you can use the CLI to ignore options, you can't use it to set which packages to be released – i.e. you still need to set the `workspaces` attribute inside the `package.json`.
 
 ## API
 
diff --git a/bin/cli.js b/bin/cli.js
index eb26b6c..7e063ab 100755
--- a/bin/cli.js
+++ b/bin/cli.js
@@ -15,11 +15,13 @@ const cli = meow(
     --first-parent Apply commit filtering to current branch only.
     --deps.bump Define deps version updating rule. Allowed: override, satisfy, inherit.
     --deps.release Define release type for dependent package if any of its deps changes. Supported values: patch, minor, major, inherit.
+	--ignore-packages  Packages' list to be ignored on bumping process
     --help Help info.
 
   Examples
     $ multi-semantic-release --debug
     $ multi-semantic-release --deps.bump=satisfy --deps.release=patch
+	$ multi-semantic-release --ignore-packages=packages/a/**,packages/b/**
 `,
 	{
 		flags: {
@@ -40,6 +42,9 @@ const cli = meow(
 				type: "string",
 				default: "patch",
 			},
+			ignorePackages: {
+				type: "string",
+			},
 			dryRun: {
 				type: "boolean",
 			},
@@ -47,6 +52,11 @@ const cli = meow(
 	}
 );
 
-const processFlags = (flags) => toPairs(flags).reduce((m, [k, v]) => set(m, k, v), {});
+const processFlags = (flags) => {
+	return toPairs(flags).reduce((m, [k, v]) => {
+		if (k === "ignorePackages" && v) return set(m, k, v.split(","));
+		return set(m, k, v);
+	}, {});
+};
 
 runner(processFlags(cli.flags));
diff --git a/bin/runner.js b/bin/runner.js
index 30ee54b..74009ea 100644
--- a/bin/runner.js
+++ b/bin/runner.js
@@ -19,7 +19,7 @@ module.exports = (flags) => {
 		console.log(`flags: ${JSON.stringify(flags, null, 2)}`);
 
 		// Get list of package.json paths according to Yarn workspaces.
-		const paths = getWorkspacesYarn(cwd);
+		const paths = getWorkspacesYarn(cwd, flags.ignorePackages);
 		console.log("yarn paths", paths);
 
 		// Do multirelease (log out any errors).
diff --git a/lib/createInlinePluginCreator.js b/lib/createInlinePluginCreator.js
index 2bedf77..5fb9e34 100644
--- a/lib/createInlinePluginCreator.js
+++ b/lib/createInlinePluginCreator.js
@@ -87,6 +87,7 @@ function createInlinePluginCreator(packages, multiContext, synchronizer, flags)
 		const analyzeCommits = async (pluginOptions, context) => {
 			const firstParentBranch = flags.firstParent ? context.branch.name : undefined;
 			pkg._preRelease = context.branch.prerelease || null;
+			pkg._branch = context.branch.name;
 
 			// Filter commits by directory.
 			commits = await getCommitsFiltered(cwd, dir, context.lastRelease.gitHead, firstParentBranch);
diff --git a/lib/getWorkspacesYarn.js b/lib/getWorkspacesYarn.js
index 4b10d76..f98727d 100644
--- a/lib/getWorkspacesYarn.js
+++ b/lib/getWorkspacesYarn.js
@@ -6,9 +6,10 @@ const { checker } = require("./blork");
  * Return array of package.json for Yarn workspaces.
  *
  * @param {string} cwd The current working directory where a package.json file can be found.
+ * @param {string[]|null} ignorePackages (Optional) Packages to be ignored passed via cli.
  * @returns {string[]} An array of package.json files corresponding to the workspaces setting in package.json
  */
-function getWorkspacesYarn(cwd) {
+function getWorkspacesYarn(cwd, ignorePackages = null) {
 	// Load package.json
 	const manifest = getManifest(`${cwd}/package.json`);
 
@@ -22,13 +23,16 @@ function getWorkspacesYarn(cwd) {
 		throw new TypeError("package.json: workspaces or workspaces.packages: Must be non-empty array of string");
 	}
 
+	// If packages to be ignored come from CLI, we need to combine them with the ones from manifest workspaces
+	if (Array.isArray(ignorePackages)) packages.push(...ignorePackages.map((p) => `!${p}`));
+
 	// Turn workspaces into list of package.json files.
 	const workspaces = glob(
 		packages.map((p) => p.replace(/\/?$/, "/package.json")),
 		{
 			cwd: cwd,
-			realpath: true,
-			ignore: "**/node_modules/**",
+			absolute: true,
+			gitignore: true,
 		}
 	);
 
diff --git a/lib/git.js b/lib/git.js
new file mode 100644
index 0000000..d86eb66
--- /dev/null
+++ b/lib/git.js
@@ -0,0 +1,30 @@
+const execa = require("execa");
+
+/**
+ * Get all the tags for a given branch.
+ *
+ * @param {String} branch The branch for which to retrieve the tags.
+ * @param {Object} [execaOptions] Options to pass to `execa`.
+ * @param {Array<String>} filters List of prefixes/sufixes to be checked inside tags.
+ *
+ * @return {Array<String>} List of git tags.
+ * @throws {Error} If the `git` command fails.
+ * @internal
+ */
+function getTags(branch, execaOptions, filters) {
+	let tags = execa.sync("git", ["tag", "--merged", branch], execaOptions).stdout;
+	tags = tags
+		.split("\n")
+		.map((tag) => tag.trim())
+		.filter(Boolean);
+
+	if (!filters || !filters.length) return tags;
+
+	const validateSubstr = (t, f) => !!f.find((v) => t.includes(v));
+
+	return tags.filter((tag) => validateSubstr(tag, filters));
+}
+
+module.exports = {
+	getTags,
+};
diff --git a/lib/glob.js b/lib/glob.js
index c9bc256..1dfe023 100644
--- a/lib/glob.js
+++ b/lib/glob.js
@@ -1,10 +1,7 @@
-const bashGlob = require("bash-glob");
-const bashPath = require("bash-path");
+const globby = require("globby");
 
 module.exports = (...args) => {
-	if (!bashPath) {
-		throw new TypeError("`bash` must be installed"); // TODO move this check to bash-glob
-	}
+	const [pattern, ...options] = args;
 
-	return bashGlob.sync(...args);
+	return globby.sync(pattern, ...options);
 };
diff --git a/lib/updateDeps.js b/lib/updateDeps.js
index 212490e..9f44d0a 100644
--- a/lib/updateDeps.js
+++ b/lib/updateDeps.js
@@ -1,6 +1,11 @@
 const { writeFileSync } = require("fs");
-const recognizeFormat = require("./recognizeFormat");
 const semver = require("semver");
+const { isObject, isEqual, transform } = require("lodash");
+const recognizeFormat = require("./recognizeFormat");
+const getManifest = require("./getManifest");
+const { getHighestVersion, getLatestVersion } = require("./utils");
+const { getTags } = require("./git");
+const debug = require("debug")("msr:updateDeps");
 
 /**
  * Resolve next package version.
@@ -17,17 +22,106 @@ const getNextVersion = (pkg) => {
 		: lastVersion || "1.0.0";
 };
 
+/**
+ * Resolve the package version from a tag
+ *
+ * @param {Package} pkg Package object.
+ * @param {string} tag The tag containing the version to resolve
+ * @returns {string} The version of the package
+ * @returns {string|null} The version of the package or null if no tag was passed
+ * @internal
+ */
+const getVersionFromTag = (pkg, tag) => {
+	if (!pkg.name) return tag || null;
+	if (!tag) return null;
+
+	const strMatch = tag.match(/[0-9].[0-9].[0-9].*/);
+	return strMatch && strMatch[0] && semver.valid(strMatch[0]) ? strMatch[0] : null;
+};
+
 /**
  * Resolve next package version on prereleases.
  *
  * @param {Package} pkg Package object.
+ * @param {Array<string>} tags Override list of tags from specific pkg and branch.
  * @returns {string|undefined} Next pkg version.
  * @internal
  */
-const getNextPreVersion = (pkg) => {
+const getNextPreVersion = (pkg, tags) => {
+	const tagFilters = [pkg._preRelease];
 	const lastVersion = pkg._lastRelease && pkg._lastRelease.version;
+	// Extract tags:
+	// 1. Set filter to extract only package tags
+	// 2. Get tags from a branch considering the filters established
+	// 3. Resolve the versions from the tags
+	// TODO: replace {cwd: '.'} with multiContext.cwd
+	if (pkg.name) tagFilters.push(pkg.name);
+	if (!tags || !tags.length) {
+		tags = getTags(pkg._branch, { cwd: "." }, tagFilters);
+	}
+	const lastPreRelTag = getPreReleaseTag(lastVersion);
+	const isNewPreRelTag = lastPreRelTag && lastPreRelTag !== pkg._preRelease;
+	const versionToSet =
+		isNewPreRelTag || !lastVersion
+			? `1.0.0-${pkg._preRelease}.1`
+			: _nextPreVersionCases(
+					tags.map((tag) => getVersionFromTag(pkg, tag)).filter((tag) => tag),
+					lastVersion,
+					pkg._nextType,
+					pkg._preRelease
+			  );
+	return versionToSet;
+};
+
+/**
+ * Parse the prerelease tag from a semver version.
+ *
+ * @param {string} version Semver version in a string format.
+ * @returns {string|null} preReleaseTag Version prerelease tag or null.
+ * @internal
+ */
+const getPreReleaseTag = (version) => {
+	const parsed = semver.parse(version);
+	if (!parsed) return null;
+	return parsed.prerelease[0] || null;
+};
+
+/**
+ * Resolve next prerelease special cases: highest version from tags or major/minor/patch.
+ *
+ * @param {Array} tags List of all released tags from package.
+ * @param {string} lastVersion Last package version released.
+ * @param {string} pkgNextType Next type evaluated for the next package type.
+ * @param {string} pkgPreRelease Package prerelease suffix.
+ * @returns {string|undefined} Next pkg version.
+ * @internal
+ */
+const _nextPreVersionCases = (tags, lastVersion, pkgNextType, pkgPreRelease) => {
+	// Case 1: Normal release on last version and is now converted to a prerelease
+	if (!semver.prerelease(lastVersion)) {
+		const { major, minor, patch } = semver.parse(lastVersion);
+		return `${semver.inc(`${major}.${minor}.${patch}`, pkgNextType || "patch")}-${pkgPreRelease}.1`;
+	}
 
-	return lastVersion ? semver.inc(lastVersion, "prerelease", pkg._preRelease) : `1.0.0-${pkg._preRelease}.1`;
+	// Case 2: Validates version with tags
+	const latestTag = getLatestVersion(tags, { withPrerelease: true });
+	return _nextPreHighestVersion(latestTag, lastVersion, pkgPreRelease);
+};
+
+/**
+ * Resolve next prerelease comparing bumped tags versions with last version.
+ *
+ * @param {string|null} latestTag Last released tag from branch or null if non-existent.
+ * @param {string} lastVersion Last version released.
+ * @param {string} pkgPreRelease Prerelease tag from package to-be-released.
+ * @returns {string} Next pkg version.
+ * @internal
+ */
+const _nextPreHighestVersion = (latestTag, lastVersion, pkgPreRelease) => {
+	const bumpFromTags = latestTag ? semver.inc(latestTag, "prerelease", pkgPreRelease) : null;
+	const bumpFromLast = semver.inc(lastVersion, "prerelease", pkgPreRelease);
+
+	return bumpFromTags ? getHighestVersion(bumpFromLast, bumpFromTags) : bumpFromLast;
 };
 
 /**
@@ -181,14 +275,61 @@ const updateManifestDeps = (pkg) => {
 			throw Error(`Cannot release because dependency ${d.name} has not been released`);
 	});
 
+	if (!auditManifestChanges(manifest, path)) {
+		return;
+	}
+
 	// Write package.json back out.
 	writeFileSync(path, JSON.stringify(manifest, null, indent) + trailingWhitespace);
 };
 
+// https://gist.github.com/Yimiprod/7ee176597fef230d1451
+const difference = (object, base) =>
+	transform(object, (result, value, key) => {
+		if (!isEqual(value, base[key])) {
+			result[key] =
+				isObject(value) && isObject(base[key]) ? difference(value, base[key]) : `${base[key]} → ${value}`;
+		}
+	});
+
+/**
+ * Clarify what exactly was changed in manifest file.
+ * @param {object} actualManifest manifest object
+ * @param {string} path manifest path
+ * @returns {boolean} has changed or not
+ * @internal
+ */
+const auditManifestChanges = (actualManifest, path) => {
+	const debugPrefix = `[${actualManifest.name}]`;
+	const oldManifest = getManifest(path);
+	const depScopes = ["dependencies", "devDependencies", "peerDependencies", "optionalDependencies"];
+	const changes = depScopes.reduce((res, scope) => {
+		const diff = difference(actualManifest[scope], oldManifest[scope]);
+
+		if (Object.keys(diff).length) {
+			res[scope] = diff;
+		}
+
+		return res;
+	}, {});
+
+	debug(debugPrefix, "package.json path=", path);
+
+	if (Object.keys(changes).length) {
+		debug(debugPrefix, "changes=", changes);
+		return true;
+	}
+
+	debug(debugPrefix, "no deps changes");
+	return false;
+};
+
 module.exports = {
 	getNextVersion,
 	getNextPreVersion,
+	getPreReleaseTag,
 	updateManifestDeps,
 	resolveReleaseType,
 	resolveNextVersion,
+	getVersionFromTag,
 };
diff --git a/lib/utils.js b/lib/utils.js
new file mode 100644
index 0000000..d027405
--- /dev/null
+++ b/lib/utils.js
@@ -0,0 +1,60 @@
+/**
+ * Lifted and tweaked from semantic-release because we follow how they bump their packages/dependencies.
+ * https://github.com/semantic-release/semantic-release/blob/master/lib/utils.js
+ */
+
+const { gt, lt, prerelease, rcompare } = require("semver");
+
+/**
+ * Get tag objects and convert them to a list of stringified versions.
+ * @param {array} tags Tags as object list.
+ * @returns {array} Tags as string list.
+ * @internal
+ */
+function tagsToVersions(tags) {
+	if (!tags) return [];
+	return tags.map(({ version }) => version);
+}
+
+/**
+ * HOC that applies highest/lowest semver function.
+ * @param {Function} predicate High order function to be called.
+ * @param {string|undefined} version1 Version 1 to be compared with.
+ * @param {string|undefined} version2 Version 2 to be compared with.
+ * @returns {string|undefined} Highest or lowest version.
+ * @internal
+ */
+const _selectVersionBy = (predicate, version1, version2) => {
+	if (predicate && version1 && version2) {
+		return predicate(version1, version2) ? version1 : version2;
+	}
+	return version1 || version2;
+};
+
+/**
+ * Gets highest semver function binding gt to the HOC selectVersionBy.
+ */
+const getHighestVersion = _selectVersionBy.bind(null, gt);
+
+/**
+ * Gets lowest semver function binding gt to the HOC selectVersionBy.
+ */
+const getLowestVersion = _selectVersionBy.bind(null, lt);
+
+/**
+ * Retrieve the latest version from a list of versions.
+ * @param {array} versions Versions as string list.
+ * @param {bool|undefined} withPrerelease Prerelease flag.
+ * @returns {string|undefined} Latest version.
+ * @internal
+ */
+function getLatestVersion(versions, withPrerelease) {
+	return versions.filter((version) => withPrerelease || !prerelease(version)).sort(rcompare)[0];
+}
+
+module.exports = {
+	tagsToVersions,
+	getHighestVersion,
+	getLowestVersion,
+	getLatestVersion,
+};
diff --git a/package.json b/package.json
index 876f629..ad2aca1 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,6 @@
 		]
 	},
 	"dependencies": {
-		"bash-glob": "^2.0.0",
 		"blork": "^9.2.2",
 		"cosmiconfig": "^7.0.0",
 		"debug": "^4.3.1",
@@ -55,6 +54,7 @@
 		"execa": "^4.1.0",
 		"get-stream": "^6.0.0",
 		"git-log-parser": "^1.2.0",
+		"globby": "11.0.2",
 		"lodash": "^4.17.20",
 		"meow": "^8.0.0",
 		"promise-events": "^0.2.1",
diff --git a/test/bin/cli.test.js b/test/bin/cli.test.js
index 136d121..ebe7d85 100644
--- a/test/bin/cli.test.js
+++ b/test/bin/cli.test.js
@@ -29,4 +29,20 @@ describe("multi-semantic-release CLI", () => {
 		expect(out).toMatch("Started multirelease! Loading 4 packages...");
 		expect(out).toMatch("Released 4 of 4 packages, semantically!");
 	});
+	test("Initial commit (changes in 2 packages, 2 filtered out)", async () => {
+		// Create Git repo with copy of Yarn workspaces fixture.
+		const cwd = gitInit();
+		copyDirectory(`test/fixtures/yarnWorkspaces/`, cwd);
+		const sha = gitCommitAll(cwd, "feat: Initial release");
+		const url = gitInitOrigin(cwd);
+		gitPush(cwd);
+
+		// Path to CLI command.
+		const filepath = `${__dirname}/../../bin/cli.js`;
+
+		// Run via command line.
+		const out = (await execa("node", [filepath, "--ignore-packages=packages/c/**,packages/d/**"], { cwd })).stdout;
+		expect(out).toMatch("Started multirelease! Loading 2 packages...");
+		expect(out).toMatch("Released 2 of 2 packages, semantically!");
+	});
 });
diff --git a/test/fixtures/yarnWorkspacesIgnore/package.json b/test/fixtures/yarnWorkspacesIgnore/package.json
new file mode 100644
index 0000000..1ecbf8d
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/package.json
@@ -0,0 +1,21 @@
+{
+	"name": "msr-test-yarn",
+	"author": "Dave Houlbrooke <dave@shax.com",
+	"version": "0.0.0-semantically-released",
+	"private": true,
+	"license": "0BSD",
+	"engines": {
+		"node": ">=8.3"
+	},
+	"workspaces": [
+		"packages/*",
+		"!packages/d/**"
+	],
+	"release": {
+		"plugins": [
+			"@semantic-release/commit-analyzer",
+			"@semantic-release/release-notes-generator"
+		],
+		"noCi": true
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnore/packages/a/package.json b/test/fixtures/yarnWorkspacesIgnore/packages/a/package.json
new file mode 100644
index 0000000..92d8046
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/packages/a/package.json
@@ -0,0 +1,8 @@
+{
+	"name": "msr-test-a",
+	"version": "0.0.0",
+	"peerDependencies": {
+		"msr-test-c": "*",
+		"left-pad": "latest"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnore/packages/b/package.json b/test/fixtures/yarnWorkspacesIgnore/packages/b/package.json
new file mode 100644
index 0000000..d4b1ec7
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/packages/b/package.json
@@ -0,0 +1,12 @@
+
+{
+	"name": "msr-test-b",
+	"version": "0.0.0",
+	"dependencies": {
+		"msr-test-a": "*"
+	},
+	"devDependencies": {
+		"msr-test-c": "*",
+		"left-pad": "latest"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnore/packages/c/.releaserc.json b/test/fixtures/yarnWorkspacesIgnore/packages/c/.releaserc.json
new file mode 100644
index 0000000..64f41b1
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/packages/c/.releaserc.json
@@ -0,0 +1,3 @@
+{
+	"tagFormat": "multi-semantic-release-test-c@v${version}"
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnore/packages/c/package.json b/test/fixtures/yarnWorkspacesIgnore/packages/c/package.json
new file mode 100644
index 0000000..0bdb127
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/packages/c/package.json
@@ -0,0 +1,8 @@
+{
+	"name": "msr-test-c",
+	"version": "0.0.0",
+	"devDependencies": {
+		"msr-test-b": "*",
+		"msr-test-d": "*"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnore/packages/d/package.json b/test/fixtures/yarnWorkspacesIgnore/packages/d/package.json
new file mode 100644
index 0000000..fa64f23
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnore/packages/d/package.json
@@ -0,0 +1,4 @@
+{
+	"name": "msr-test-d",
+	"version": "0.0.0"
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/package.json b/test/fixtures/yarnWorkspacesIgnoreSplit/package.json
new file mode 100644
index 0000000..f37304b
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/package.json
@@ -0,0 +1,23 @@
+{
+	"name": "msr-test-yarn",
+	"author": "Dave Houlbrooke <dave@shax.com",
+	"version": "0.0.0-semantically-released",
+	"private": true,
+	"license": "0BSD",
+	"engines": {
+		"node": ">=8.3"
+	},
+	"workspaces": [
+		"packages/a",
+		"!packages/b",
+		"packages/c",
+		"!packages/d"
+	],
+	"release": {
+		"plugins": [
+			"@semantic-release/commit-analyzer",
+			"@semantic-release/release-notes-generator"
+		],
+		"noCi": true
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/packages/a/package.json b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/a/package.json
new file mode 100644
index 0000000..92d8046
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/a/package.json
@@ -0,0 +1,8 @@
+{
+	"name": "msr-test-a",
+	"version": "0.0.0",
+	"peerDependencies": {
+		"msr-test-c": "*",
+		"left-pad": "latest"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/packages/b/package.json b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/b/package.json
new file mode 100644
index 0000000..1812781
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/b/package.json
@@ -0,0 +1,11 @@
+{
+	"name": "msr-test-b",
+	"version": "0.0.0",
+	"dependencies": {
+		"msr-test-a": "*"
+	},
+	"devDependencies": {
+		"msr-test-c": "*",
+		"left-pad": "latest"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/.releaserc.json b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/.releaserc.json
new file mode 100644
index 0000000..64f41b1
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/.releaserc.json
@@ -0,0 +1,3 @@
+{
+	"tagFormat": "multi-semantic-release-test-c@v${version}"
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/package.json b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/package.json
new file mode 100644
index 0000000..0bdb127
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/c/package.json
@@ -0,0 +1,8 @@
+{
+	"name": "msr-test-c",
+	"version": "0.0.0",
+	"devDependencies": {
+		"msr-test-b": "*",
+		"msr-test-d": "*"
+	}
+}
\ No newline at end of file
diff --git a/test/fixtures/yarnWorkspacesIgnoreSplit/packages/d/package.json b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/d/package.json
new file mode 100644
index 0000000..fa64f23
--- /dev/null
+++ b/test/fixtures/yarnWorkspacesIgnoreSplit/packages/d/package.json
@@ -0,0 +1,4 @@
+{
+	"name": "msr-test-d",
+	"version": "0.0.0"
+}
\ No newline at end of file
diff --git a/test/lib/getWorkspacesYarn.test.js b/test/lib/getWorkspacesYarn.test.js
index 8361e78..1aa34cf 100644
--- a/test/lib/getWorkspacesYarn.test.js
+++ b/test/lib/getWorkspacesYarn.test.js
@@ -12,6 +12,41 @@ describe("getWorkspacesYarn()", () => {
 			`${resolved}/packages/d/package.json`,
 		]);
 	});
+	test("Should ignore some packages", () => {
+		const resolved = resolve(`${__dirname}/../fixtures/yarnWorkspacesIgnore`);
+		expect(getWorkspacesYarn(resolved)).toEqual([
+			`${resolved}/packages/a/package.json`,
+			`${resolved}/packages/b/package.json`,
+			`${resolved}/packages/c/package.json`,
+		]);
+
+		const resolvedSplit = resolve(`${__dirname}/../fixtures/yarnWorkspacesIgnoreSplit`);
+		expect(getWorkspacesYarn(resolvedSplit)).toEqual([
+			`${resolvedSplit}/packages/a/package.json`,
+			`${resolvedSplit}/packages/c/package.json`,
+		]);
+	});
+	test("Should ignore some packages via CLI", () => {
+		const resolved = resolve(`${__dirname}/../fixtures/yarnWorkspacesIgnore`);
+		expect(getWorkspacesYarn(resolved, ["packages/a/**", "packages/b/**"])).toEqual([
+			`${resolved}/packages/c/package.json`,
+		]);
+
+		const resolvedSplit = resolve(`${__dirname}/../fixtures/yarnWorkspacesIgnoreSplit`);
+		expect(getWorkspacesYarn(resolvedSplit, ["packages/b", "packages/d"])).toEqual([
+			`${resolvedSplit}/packages/a/package.json`,
+			`${resolvedSplit}/packages/c/package.json`,
+		]);
+	});
+	test("Should throw when ignored packages from CLI and workspaces sets an empty workspace list to be processed", () => {
+		const resolved = resolve(`${__dirname}/../fixtures/yarnWorkspacesIgnore`);
+		expect(() => getWorkspacesYarn(resolved, ["packages/a/**", "packages/b/**", "packages/c/**"])).toThrow(
+			TypeError
+		);
+		expect(() => getWorkspacesYarn(resolved, ["packages/a/**", "packages/b/**", "packages/c/**"])).toThrow(
+			"package.json: workspaces: Must contain one or more workspaces"
+		);
+	});
 	test("TypeError if bad workspaces setting", () => {
 		const resolved = resolve(`${__dirname}/../fixtures/badYarnWorkspaces`);
 		expect(() => getWorkspacesYarn(resolved)).toThrow(TypeError);
@@ -36,15 +71,4 @@ describe("getWorkspacesYarn()", () => {
 			`${resolved}/packages/d/package.json`,
 		]);
 	});
-	test("Checks `bash` to be installed", () => {
-		jest.isolateModules(() => {
-			jest.resetModules();
-			jest.mock("bash-path", () => undefined);
-
-			const resolved = resolve(`${__dirname}/../fixtures/yarnWorkspaces`);
-			const getWorkspaces = require("../../lib/getWorkspacesYarn");
-
-			expect(() => getWorkspaces(resolved)).toThrowError("`bash` must be installed");
-		});
-	});
 });
diff --git a/test/lib/git.test.js b/test/lib/git.test.js
new file mode 100644
index 0000000..d437d09
--- /dev/null
+++ b/test/lib/git.test.js
@@ -0,0 +1,90 @@
+const tempy = require("tempy");
+const { WritableStreamBuffer } = require("stream-buffers");
+const { copyDirectory, createNewTestingFiles } = require("../helpers/file");
+const { gitInit, gitCommitAll, gitInitOrigin, gitPush } = require("../helpers/git");
+const { getTags } = require("../../lib/git");
+
+test("Fetch all tags on master after two package release", async () => {
+	const packages = ["packages/c/", "packages/d/"];
+
+	// Create Git repo with copy of Yarn workspaces fixture.
+	const cwd = gitInit("master", "release");
+	copyDirectory(`test/fixtures/yarnWorkspaces2Packages/`, cwd);
+	const sha1 = gitCommitAll(cwd, "feat: Initial release");
+	gitInitOrigin(cwd, "release");
+	gitPush(cwd);
+
+	const stdout = new WritableStreamBuffer();
+	const stderr = new WritableStreamBuffer();
+
+	// Call multiSemanticRelease()
+	// Doesn't include plugins that actually publish.
+	const multiSemanticRelease = require("../../");
+	await multiSemanticRelease(
+		packages.map((folder) => `${folder}package.json`),
+		{
+			branches: [{ name: "master" }, { name: "release" }],
+		},
+		{ cwd, stdout, stderr }
+	);
+
+	const tags = getTags("master", { cwd }).sort();
+	expect(tags).toEqual(["msr-test-d@1.0.0", "msr-test-c@1.0.0"].sort());
+});
+
+test("Fetch only prerelease tags", async () => {
+	const packages = ["packages/c/", "packages/d/"];
+
+	// Create Git repo with copy of Yarn workspaces fixture.
+	const cwd = gitInit("master", "release");
+	copyDirectory(`test/fixtures/yarnWorkspaces2Packages/`, cwd);
+	const sha1 = gitCommitAll(cwd, "feat: Initial release");
+	gitInitOrigin(cwd, "release");
+	gitPush(cwd);
+
+	let stdout = new WritableStreamBuffer();
+	let stderr = new WritableStreamBuffer();
+
+	// Call multiSemanticRelease()
+	// Doesn't include plugins that actually publish.
+	const multiSemanticRelease = require("../../");
+	await multiSemanticRelease(
+		packages.map((folder) => `${folder}package.json`),
+		{
+			branches: [{ name: "master" }, { name: "release" }],
+		},
+		{ cwd, stdout, stderr }
+	);
+
+	// Add new testing files for a new release.
+	createNewTestingFiles(packages, cwd);
+	const sha = gitCommitAll(cwd, "feat: New prerelease\n\nBREAKING CHANGE: bump to bigger value");
+	gitPush(cwd);
+
+	// Capture output.
+	stdout = new WritableStreamBuffer();
+	stderr = new WritableStreamBuffer();
+
+	// Call multiSemanticRelease() for a second release
+	// Doesn't include plugins that actually publish.
+	// Change the master branch from release to prerelease to test bumping.
+	await multiSemanticRelease(
+		packages.map((folder) => `${folder}package.json`),
+		{
+			branches: [{ name: "master", prerelease: "beta" }, { name: "release" }],
+		},
+		{ cwd, stdout, stderr }
+	);
+
+	const tags = getTags("master", { cwd }, ["beta"]).sort();
+	expect(tags).toEqual(["msr-test-d@2.0.0-beta.1", "msr-test-c@2.0.0-beta.1"].sort());
+});
+
+test("Throws error if obtaining the tags fails", () => {
+	const cwd = tempy.directory();
+
+	const t = () => {
+		getTags("master", { cwd });
+	};
+	expect(t).toThrow(Error);
+});
diff --git a/test/lib/multiSemanticRelease.test.js b/test/lib/multiSemanticRelease.test.js
index 33ce263..a08da33 100644
--- a/test/lib/multiSemanticRelease.test.js
+++ b/test/lib/multiSemanticRelease.test.js
@@ -352,6 +352,98 @@ describe("multiSemanticRelease()", () => {
 			},
 		});
 	});
+	test("Two separate releases (release to prerelease)", async () => {
+		const packages = ["packages/c/", "packages/d/"];
+
+		// Create Git repo with copy of Yarn workspaces fixture.
+		const cwd = gitInit("master", "release");
+		copyDirectory(`test/fixtures/yarnWorkspaces2Packages/`, cwd);
+		const sha1 = gitCommitAll(cwd, "feat: Initial release");
+		gitInitOrigin(cwd, "release");
+		gitPush(cwd);
+
+		let stdout = new WritableStreamBuffer();
+		let stderr = new WritableStreamBuffer();
+
+		// Call multiSemanticRelease()
+		// Doesn't include plugins that actually publish.
+		const multiSemanticRelease = require("../../");
+		let result = await multiSemanticRelease(
+			packages.map((folder) => `${folder}package.json`),
+			{
+				branches: [{ name: "master" }, { name: "release" }],
+			},
+			{ cwd, stdout, stderr }
+		);
+
+		// Add new testing files for a new release.
+		createNewTestingFiles(packages, cwd);
+		const sha = gitCommitAll(cwd, "feat: New prerelease\n\nBREAKING CHANGE: bump to bigger value");
+		gitPush(cwd);
+
+		// Capture output.
+		stdout = new WritableStreamBuffer();
+		stderr = new WritableStreamBuffer();
+
+		// Call multiSemanticRelease() for a second release
+		// Doesn't include plugins that actually publish.
+		// Change the master branch from release to prerelease to test bumping.
+		result = await multiSemanticRelease(
+			packages.map((folder) => `${folder}package.json`),
+			{
+				branches: [{ name: "master", prerelease: "beta" }, { name: "release" }],
+			},
+			{ cwd, stdout, stderr }
+		);
+
+		// Get stdout and stderr output.
+		const err = stderr.getContentsAsString("utf8");
+		expect(err).toBe(false);
+		const out = stdout.getContentsAsString("utf8");
+		expect(out).toMatch("Started multirelease! Loading 2 packages...");
+		expect(out).toMatch("Loaded package msr-test-c");
+		expect(out).toMatch("Loaded package msr-test-d");
+		expect(out).toMatch("Queued 2 packages! Starting release...");
+		expect(out).toMatch("Created tag msr-test-c@2.0.0-beta.1");
+		expect(out).toMatch("Created tag msr-test-d@2.0.0-beta.1");
+		expect(out).toMatch("Released 2 of 2 packages, semantically!");
+
+		// D.
+		expect(result[0].name).toBe("msr-test-c");
+		expect(result[0].result.lastRelease).toEqual({
+			channels: [null],
+			gitHead: sha1,
+			gitTag: "msr-test-c@1.0.0",
+			name: "msr-test-c@1.0.0",
+			version: "1.0.0",
+		});
+		expect(result[0].result.nextRelease).toMatchObject({
+			gitHead: sha,
+			gitTag: "msr-test-c@2.0.0-beta.1",
+			type: "major",
+			version: "2.0.0-beta.1",
+		});
+
+		expect(result[0].result.nextRelease.notes).toMatch("# msr-test-c [2.0.0-beta.1]");
+		expect(result[0].result.nextRelease.notes).toMatch("### Features\n\n* New prerelease");
+		expect(result[0].result.nextRelease.notes).toMatch(
+			"### Dependencies\n\n* **msr-test-d:** upgraded to 2.0.0-beta.1"
+		);
+
+		expect(result[1].result.nextRelease.notes).toMatch("# msr-test-d [2.0.0-beta.1]");
+		expect(result[1].result.nextRelease.notes).toMatch("### Features\n\n* New prerelease");
+		expect(result[1].result.nextRelease.notes).not.toMatch("### Dependencies");
+
+		// ONLY 1 time.
+		expect(result).toHaveLength(2);
+
+		// Check manifests.
+		expect(require(`${cwd}/packages/c/package.json`)).toMatchObject({
+			dependencies: {
+				"msr-test-d": "2.0.0-beta.1",
+			},
+		});
+	}, 10000);
 	test("Two separate releases (changes in all packages with prereleases)", async () => {
 		const packages = ["packages/a/", "packages/b/", "packages/c/", "packages/d/"];
 
@@ -516,7 +608,7 @@ describe("multiSemanticRelease()", () => {
 				"msr-test-d": "1.0.0-dev.2",
 			},
 		});
-	});
+	}, 10000);
 	test("No changes in any packages", async () => {
 		// Create Git repo with copy of Yarn workspaces fixture.
 		const cwd = gitInit();
diff --git a/test/lib/updateDeps.test.js b/test/lib/updateDeps.test.js
index f4d1b95..1b6f89d 100644
--- a/test/lib/updateDeps.test.js
+++ b/test/lib/updateDeps.test.js
@@ -1,4 +1,11 @@
-const { resolveReleaseType, resolveNextVersion, getNextVersion, getNextPreVersion } = require("../../lib/updateDeps");
+const {
+	resolveReleaseType,
+	resolveNextVersion,
+	getNextVersion,
+	getNextPreVersion,
+	getPreReleaseTag,
+	getVersionFromTag,
+} = require("../../lib/updateDeps");
 
 describe("resolveNextVersion()", () => {
 	// prettier-ignore
@@ -153,12 +160,13 @@ describe("getNextVersion()", () => {
 		["1.0.0-dev.1", "patch", "1.0.0"],
 	]
 
-	cases.forEach(([lastVersion, releaseType, nextVersion]) => {
+	cases.forEach(([lastVersion, releaseType, nextVersion, preRelease]) => {
 		it(`${lastVersion} and ${releaseType} gives ${nextVersion}`, () => {
 			// prettier-ignore
 			expect(getNextVersion({
 				_nextType: releaseType,
-				_lastRelease: {version: lastVersion}
+				_lastRelease: {version: lastVersion},
+				_preRelease: preRelease
 			})).toBe(nextVersion);
 		});
 	});
@@ -167,21 +175,89 @@ describe("getNextVersion()", () => {
 describe("getNextPreVersion()", () => {
 	// prettier-ignore
 	const cases = [
-		[undefined, "patch", "rc", "1.0.0-rc.1"],
-		[undefined, "patch", "rc", "1.0.0-rc.1"],
-		["1.0.0-rc.0", "minor", "dev", "1.0.0-dev.0"],
-		["1.0.0-dev.0", "major", "dev", "1.0.0-dev.1"],
-		
+		[undefined, "patch", "rc", [], "1.0.0-rc.1"],
+		[undefined, "patch", "rc", [], "1.0.0-rc.1"],
+		[null, "patch", "rc", [], "1.0.0-rc.1"],
+		[null, "patch", "rc", [], "1.0.0-rc.1"],
+		["1.0.0-rc.0", "minor", "dev", [], "1.0.0-dev.1"],
+		["1.0.0-dev.0", "major", "dev", [], "1.0.0-dev.1"],
+		["1.0.0-dev.0", "major", "dev", ["1.0.0-dev.1"], "1.0.0-dev.2"],
+		["1.0.0-dev.0", "major", "dev", ["1.0.0-dev.1", "1.0.1-dev.0"], "1.0.1-dev.1"],
+		["11.0.0", "major", "beta", [], "12.0.0-beta.1"],
+		["1.0.0", "minor", "beta", [], "1.1.0-beta.1"],
+		["1.0.0", "patch", "beta", [], "1.0.1-beta.1"],
 	]
 
-	cases.forEach(([lastVersion, releaseType, preRelease, nextVersion]) => {
-		it(`${lastVersion} and ${releaseType} gives ${nextVersion}`, () => {
+	cases.forEach(([lastVersion, releaseType, preRelease, lastTags, nextVersion]) => {
+		it(`${lastVersion} and ${releaseType} ${
+			lastTags.length ? "with existent tags " : ""
+		}gives ${nextVersion}`, () => {
 			// prettier-ignore
-			expect(getNextPreVersion({
-				_nextType: releaseType,
-				_lastRelease: {version: lastVersion},
-				_preRelease: preRelease
-			})).toBe(nextVersion);
+			expect(getNextPreVersion(
+				{
+					_nextType: releaseType,
+					_lastRelease: {version: lastVersion},
+					_preRelease: preRelease,
+					_branch: "master",
+				},
+				lastTags
+			)).toBe(nextVersion);
+		});
+	});
+});
+
+describe("getPreReleaseTag()", () => {
+	// prettier-ignore
+	const cases = [
+		[undefined, null],
+		[null, null],
+		["1.0.0-rc.0", "rc"],
+		["1.0.0-dev.0", "dev"],
+		["1.0.0-dev.2", "dev"],
+		["1.1.0-beta.0", "beta"],
+		["11.0.0", null],
+		["11.1.0", null],
+		["11.0.1", null],
+	]
+
+	cases.forEach(([version, preReleaseTag]) => {
+		it(`${version} gives ${preReleaseTag}`, () => {
+			// prettier-ignore
+			expect(getPreReleaseTag(version)).toBe(preReleaseTag);
+		});
+	});
+});
+
+describe("getVersionFromTag()", () => {
+	// prettier-ignore
+	const cases = [
+		[{}, undefined, null],
+		[{ name: undefined }, undefined, null],
+		[{}, null, null],
+		[{ name: null }, null, null],
+		[{ name: undefined }, '1.0.0', '1.0.0'],
+		[{ name: null }, '1.0.0', '1.0.0'],
+		[{ name: 'abc' }, undefined, null],
+		[{ name: 'abc' }, null, null],
+		[{ name: 'abc' }, '1.0.0', '1.0.0'],
+		[{ name: 'dev' }, '1.0.0-dev.1', '1.0.0-dev.1'],
+		[{ name: 'app' }, 'app@1.0.0-dev.1', '1.0.0-dev.1'],
+		[{ name: 'app' }, 'app@1.0.0-devapp@.1', null],
+		[{ name: 'msr-test-a' }, 'msr-test-a@1.0.0-rc.1', '1.0.0-rc.1'],
+		[{ name: 'msr.test.a' }, 'msr.test.a@1.0.0', '1.0.0'],
+		[{ name: 'msr_test_a' }, 'msr_test_a@1.0.0', '1.0.0'],
+		[{ name: 'msr@test@a' }, 'msr@test@a@1.0.0', '1.0.0'],
+		[{ name: 'abc' }, 'a.b.c-rc.0', null],
+		[{ name: 'abc' }, '1-rc.0', null],
+		[{ name: 'abc' }, '1.0.x-rc.0', null],
+		[{ name: 'abc' }, '1.x.0-rc.0', null],
+		[{ name: 'abc' }, 'x.1.0-rc.0', null],
+	]
+
+	cases.forEach(([pkg, tag, versionFromTag]) => {
+		it(`${JSON.stringify(pkg)} pkg with tag ${tag} gives ${versionFromTag}`, () => {
+			// prettier-ignore
+			expect(getVersionFromTag(pkg, tag)).toBe(versionFromTag);
 		});
 	});
 });
diff --git a/test/lib/utils.test.js b/test/lib/utils.test.js
new file mode 100644
index 0000000..1990261
--- /dev/null
+++ b/test/lib/utils.test.js
@@ -0,0 +1,69 @@
+const { tag } = require("semantic-release/lib/git");
+const { getHighestVersion, getLowestVersion, getLatestVersion, tagsToVersions } = require("../../lib/utils");
+
+describe("tagsToVersions()", () => {
+	// prettier-ignore
+	const cases = [
+        [[{version: "1.0.0"}, {version: "1.1.0"}, {version: "1.2.0"}], ["1.0.0", "1.1.0", "1.2.0"]],
+        [[],[]],
+        [undefined, []],
+        [null, []],
+	]
+
+	cases.forEach(([tags, versions]) => {
+		it(`${tags} gives versions as ${versions}`, () => {
+			expect(tagsToVersions(tags)).toStrictEqual(versions);
+		});
+	});
+});
+
+describe("getHighestVersion()", () => {
+	// prettier-ignore
+	const cases = [
+		["1.0.0", "2.0.0", "2.0.0"],
+        ["1.1.1", "1.0.0", "1.1.1"],
+        [null, "1.0.0", "1.0.0"],
+        ["1.0.0", undefined, "1.0.0"],
+        [undefined, undefined, undefined],
+	]
+
+	cases.forEach(([version1, version2, high]) => {
+		it(`${version1}/${version2} gives highest as ${high}`, () => {
+			expect(getHighestVersion(version1, version2)).toBe(high);
+		});
+	});
+});
+
+describe("getLowestVersion()", () => {
+	// prettier-ignore
+	const cases = [
+		["1.0.0", "2.0.0", "1.0.0"],
+        ["1.1.1", "1.0.0", "1.0.0"],
+        [null, "1.0.0", "1.0.0"],
+        ["1.0.0", undefined, "1.0.0"],
+        [undefined, undefined, undefined],
+	]
+
+	cases.forEach(([version1, version2, low]) => {
+		it(`${version1}/${version2} gives lowest as ${low}`, () => {
+			expect(getLowestVersion(version1, version2, 0)).toBe(low);
+		});
+	});
+});
+
+describe("getLatestVersion()", () => {
+	// prettier-ignore
+	const cases = [
+		[["1.2.3-alpha.3", "1.2.0", "1.0.1", "1.0.0-alpha.1"], null, "1.2.0"],
+        [["1.2.3-alpha.3", "1.2.3-alpha.2"], null, undefined],
+        [["1.2.3-alpha.3", "1.2.0", "1.0.1", "1.0.0-alpha.1"], true, "1.2.3-alpha.3"],
+        [["1.2.3-alpha.3", "1.2.3-alpha.2"], true, "1.2.3-alpha.3"],
+        [[], {}, undefined]
+	]
+
+	cases.forEach(([versions, withPrerelease, latest]) => {
+		it(`${versions}/${withPrerelease} gives latest as ${latest}`, () => {
+			expect(getLatestVersion(versions, withPrerelease)).toBe(latest);
+		});
+	});
+});
diff --git a/yarn.lock b/yarn.lock
index b6c2481..7b75f10 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1326,27 +1326,6 @@ base@^0.11.1:
     mixin-deep "^1.2.0"
     pascalcase "^0.1.1"
 
-bash-glob@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/bash-glob/-/bash-glob-2.0.0.tgz#a8ef19450783403ed93fccca2dbe09f2cf6320dc"
-  integrity sha512-53/NJ+t2UAkEYgQPO6aFjbx1Ue8vNNXCYaA4EljNKP1SR8A9dSQQoBmYWR8BLXO0/NDRJEMSJ4BxWihi//m3Kw==
-  dependencies:
-    bash-path "^1.0.1"
-    component-emitter "^1.2.1"
-    cross-spawn "^5.1.0"
-    each-parallel-async "^1.0.0"
-    extend-shallow "^2.0.1"
-    is-extglob "^2.1.1"
-    is-glob "^4.0.0"
-
-bash-path@^1.0.1:
-  version "1.0.3"
-  resolved "https://registry.yarnpkg.com/bash-path/-/bash-path-1.0.3.tgz#dbc9efbdf18b1c11413dcb59b960e6aa56c84258"
-  integrity sha512-mGrYvOa6yTY/qNCiZkPFJqWmODK68y6kmVRAJ1NNbWlNoJrUrsFxu7FU2EKg7gbrer6ttrKkF2s/E/lhRy7/OA==
-  dependencies:
-    arr-union "^3.1.0"
-    is-windows "^1.0.1"
-
 bcrypt-pbkdf@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/bcrypt-pbkdf/-/bcrypt-pbkdf-1.0.2.tgz#a4301d389b6a43f9b67ff3ca11a3f6637e360e9e"
@@ -1964,7 +1943,7 @@ create-error-class@^3.0.0:
   dependencies:
     capture-stack-trace "^1.0.0"
 
-cross-spawn@^5.0.1, cross-spawn@^5.1.0:
+cross-spawn@^5.0.1:
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-5.1.0.tgz#e8bd0efee58fcff6f8f94510a0a554bbfa235449"
   integrity sha1-6L0O/uWPz/b4+UUQoKVUu/ojVEk=
@@ -2289,11 +2268,6 @@ duplexify@^3.4.2, duplexify@^3.6.0:
     readable-stream "^2.0.0"
     stream-shift "^1.0.0"
 
-each-parallel-async@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/each-parallel-async/-/each-parallel-async-1.0.0.tgz#91783e190000c7dd588336b2d468ebaf71980f7b"
-  integrity sha512-P/9kLQiQj0vZNzphvKKTgRgMnlqs5cJsxeAiuog1jrUnwv0Z3hVUwJDQiP7MnLb2I9S15nR9SRUceFT9IxtqRg==
-
 ecc-jsbn@~0.1.1:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/ecc-jsbn/-/ecc-jsbn-0.1.2.tgz#3a83a904e54353287874c564b7549386849a98c9"
@@ -3126,6 +3100,18 @@ globals@^12.1.0:
   dependencies:
     type-fest "^0.8.1"
 
+globby@11.0.2:
+  version "11.0.2"
+  resolved "https://registry.yarnpkg.com/globby/-/globby-11.0.2.tgz#1af538b766a3b540ebfb58a32b2e2d5897321d83"
+  integrity sha512-2ZThXDvvV8fYFRVIxnrMQBipZQDr7MxKAmQK1vujaj9/7eF0efG7BPUKJ7jP7G5SLF37xKDXvO4S/KKLj/Z0og==
+  dependencies:
+    array-union "^2.1.0"
+    dir-glob "^3.0.1"
+    fast-glob "^3.1.1"
+    ignore "^5.1.4"
+    merge2 "^1.3.0"
+    slash "^3.0.0"
+
 globby@^11.0.0, globby@^11.0.1:
   version "11.0.1"
   resolved "https://registry.yarnpkg.com/globby/-/globby-11.0.1.tgz#9a2bf107a068f3ffeabc49ad702c79ede8cfd357"
@@ -3766,7 +3752,7 @@ is-typedarray@^1.0.0, is-typedarray@~1.0.0:
   resolved "https://registry.yarnpkg.com/is-typedarray/-/is-typedarray-1.0.0.tgz#e479c80858df0c1b11ddda6940f96011fcda4a9a"
   integrity sha1-5HnICFjfDBsR3dppQPlgEfzaSpo=
 
-is-windows@^1.0.1, is-windows@^1.0.2:
+is-windows@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-1.0.2.tgz#d1850eb9791ecd18e6182ce12a30f396634bb19d"
   integrity sha512-eXK1UInq2bPmjyX6e3VHIzMLobc4J94i4AWn+Hpq3OU5KkrRC96OAcR3PRJ/pGu6m8TRnBHP9dkXQVsT/COVIA==