Fix input validation patterns for resource ids (#2086)

* Fix input element pattern matching and add validation reporting for
cases where the element is not within a form element.

* Update test snapshots.

* Remove old code and fix trigger error message.

* Move id validation to a util class.

* Add unit tests, fix standalone function, rename constants.

src/Utils/ValidationUtils.test.ts

@@ -0,0 +1,18 @@
+import { IsValidCosmosDbResourceId } from "Utils/ValidationUtils";
+
+const testCases = [
+  ["validId", true],
+  ["forward/slash", false],
+  ["back\\slash", false],
+  ["question?mark", false],
+  ["hash#mark", false],
+  ["?invalidstart", false],
+  ["invalidEnd/", false],
+  ["space-at-end ", false],
+];
+
+describe("IsValidCosmosDbResourceId", () => {
+  test.each(testCases)("IsValidCosmosDbResourceId(%p). Expected: %p", (id: string, expected: boolean) => {
+    expect(IsValidCosmosDbResourceId(id)).toBe(expected);
+  });
+});

src/Utils/ValidationUtils.ts

@@ -0,0 +1,24 @@
+//
+// Common methods and constants for validation
+//
+
+//
+// Validation of id for Cosmos DB resources:
+// - Database
+// - Container
+// - Stored Procedure
+// - User Defined Function (UDF)
+// - Trigger
+//
+// Use these with <input> elements
+// eslint-disable-next-line no-useless-escape
+export const ValidCosmosDbIdInputPattern: RegExp = /[^\/?#\\]*[^\/?# \\]/;
+export const ValidCosmosDbIdDescription: string = "May not end with space nor contain characters '\\' '/' '#' '?'";
+
+// For a standalone function regex, we need to wrap the previous reg expression,
+// to test against the entire value. This is done implicitly by input elements.
+const ValidCosmosDbIdRegex: RegExp = new RegExp(`^(?:${ValidCosmosDbIdInputPattern.source})$`);
+
+export function IsValidCosmosDbResourceId(id: string): boolean {
+  return id && ValidCosmosDbIdRegex.test(id);
+}