write a very simple parser for query

public/app/overrides/models/query.spec.ts

@@ -0,0 +1,54 @@
+import { brandQuery } from '@webapp/models/query';
+import { parse } from './query';
+
+const cases: Array<
+  [string, { profileId: string; tags?: Record<string, string> }]
+> = [
+  ['{}', { profileId: '' }],
+  [
+    'process_cpu:cpu:nanoseconds:cpu:nanoseconds{}',
+    { profileId: 'process_cpu:cpu:nanoseconds:cpu:nanoseconds' },
+  ],
+  [
+    'process_cpu:cpu:nanoseconds:cpu:nanoseconds{tag="mytag"}',
+    {
+      profileId: 'process_cpu:cpu:nanoseconds:cpu:nanoseconds',
+      tags: {
+        tag: 'mytag',
+      },
+    },
+  ],
+  [
+    'process_cpu:cpu:nanoseconds:cpu:nanoseconds{tag="mytag", tag2="mytag2"}',
+    {
+      profileId: 'process_cpu:cpu:nanoseconds:cpu:nanoseconds',
+      tags: {
+        tag: 'mytag',
+        tag2: 'mytag2',
+      },
+    },
+  ],
+  [
+    'process_cpu:cpu:nanoseconds:cpu:nanoseconds{tag="mytag",tag2="mytag2"}',
+    {
+      profileId: 'process_cpu:cpu:nanoseconds:cpu:nanoseconds',
+      tags: {
+        tag: 'mytag',
+        tag2: 'mytag2',
+      },
+    },
+  ],
+  [
+    'process_cpu:cpu:nanoseconds:cpu:nanoseconds{tag="my.ta/g_"}',
+    {
+      profileId: 'process_cpu:cpu:nanoseconds:cpu:nanoseconds',
+      tags: {
+        tag: 'my.ta/g_',
+      },
+    },
+  ],
+];
+
+test.each(cases)('parse(%s) should be %s', (query, expected) => {
+  expect(parse(brandQuery(query))).toEqual(expected);
+});

public/app/overrides/models/query.ts

@@ -0,0 +1,39 @@
+import { Query } from '@webapp/models/query';
+
+// ParseQuery parses a string of $app_name<{<$tag_matchers>}> form.
+// It assumes the query is well formed
+export function parse(query: Query): {
+  profileId: string;
+  tags?: Record<string, string>;
+} {
+  const regex = /(.+){(.*)}/;
+  const match = query.match(regex);
+
+  if (!match) {
+    // TODO: return a Nothing() ?
+    return { profileId: '' };
+  }
+
+  const [_original, head, tail] = match;
+  const tags = parseTags(tail);
+
+  if (!Object.keys(tags).length) {
+    return { profileId: head };
+  }
+  return { profileId: head, tags };
+}
+
+function parseTags(s: string) {
+  const pattern = /(\w+)="([^"]+)/g;
+
+  let match;
+  const matches: Record<string, string> = {};
+
+  while ((match = pattern.exec(s)) !== null) {
+    const key = match[1];
+    const value = match[2];
+    matches[key] = value;
+  }
+
+  return matches;
+}