1 files changed, 56 insertions, 0 deletions
diff --git a/packages/monorepo-scripts/src/utils/semver_utils.ts b/packages/monorepo-scripts/src/utils/semver_utils.ts
new file mode 100644
index 000000000..d5c6b2d17
--- /dev/null
+++ b/packages/monorepo-scripts/src/utils/semver_utils.ts
@@ -0,0 +1,56 @@
+import * as _ from 'lodash';
+import semverSort = require('semver-sort');
+
+// Regex that matches semantic versions only including digits and dots.
+const SEM_VER_REGEX = /^(\d+\.){1}(\d+\.){1}(\d+){1}$/gm;
+
+export const semverUtils = {
+    /**
+     * Checks whether version a is lessThan version b. Supplied versions must be
+     * Semantic Versions containing only numbers and dots (e.g 1.4.0).
+     * @param a version of interest
+     * @param b version to compare a against
+     * @return Whether version a is lessThan version b
+     */
+    lessThan(a: string, b: string): boolean {
+        this.assertValidSemVer('a', a);
+        this.assertValidSemVer('b', b);
+        if (a === b) {
+            return false;
+        }
+        const sortedVersions = semverSort.desc([a, b]);
+        const isALessThanB = sortedVersions[0] === b;
+        return isALessThanB;
+    },
+    /**
+     * Checks whether version a is greaterThan version b. Supplied versions must be
+     * Semantic Versions containing only numbers and dots (e.g 1.4.0).
+     * @param a version of interest
+     * @param b version to compare a against
+     * @return Whether version a is greaterThan version b
+     */
+    greaterThan(a: string, b: string): boolean {
+        this.assertValidSemVer('a', a);
+        this.assertValidSemVer('b', b);
+        if (a === b) {
+            return false;
+        }
+        const sortedVersions = semverSort.desc([a, b]);
+        const isAGreaterThanB = sortedVersions[0] === a;
+        return isAGreaterThanB;
+    },
+    assertValidSemVer(variableName: string, version: string): void {
+        if (!version.match(SEM_VER_REGEX)) {
+            throw new Error(
+                `SemVer versions should only contain numbers and dots. Encountered: ${variableName} = ${version}`,
+            );
+        }
+    },
+    getLatestVersion(versions: string[]): string {
+        _.each(versions, version => {
+            this.assertValidSemVer('version', version);
+        });
+        const sortedVersions = semverSort.desc(versions);
+        return sortedVersions[0];
+    },
+};