Add analysis-kinds input and parse it

src/analyses.ts

@@ -1,4 +1,40 @@
+import { ConfigurationError } from "./util";
+
 export enum AnalysisKind {
   CodeScanning = "code-scanning",
   CodeQuality = "code-quality",
 }
+
+// Exported for testing. A set of all known analysis kinds.
+export const supportedAnalysisKinds = new Set(Object.values(AnalysisKind));
+
+/**
+ * Parses a comma-separated string into a list of unique analysis kinds.
+ * Throws a configuration error if the input contains unknown analysis kinds
+ * or doesn't contain at least one element.
+ *
+ * @param input The comma-separated string to parse.
+ * @returns The array of unique analysis kinds that were parsed from the input string.
+ */
+export async function parseAnalysisKinds(
+  input: string,
+): Promise<AnalysisKind[]> {
+  const components = input.split(",");
+
+  if (components.length < 1) {
+    throw new ConfigurationError(
+      "At least one analysis kind must be configured.",
+    );
+  }
+
+  for (const component of components) {
+    if (!supportedAnalysisKinds.has(component as AnalysisKind)) {
+      throw new ConfigurationError(`Unknown analysis kind: ${component}`);
+    }
+  }
+
+  // Return all unique elements.
+  return Array.from(
+    new Set(components.map((component) => component as AnalysisKind)),
+  );
+}