Fix duplicate chart metrics when removing a filter

.claude/commands/fix-flakey-test.md

@@ -0,0 +1 @@
+Fix flakey test $ARGUMENTS

.claude/commands/fix-issue.md

@@ -0,0 +1 @@
+Fix issue $ARGUMENTS

.claude/commands/fix-pr.md

@@ -0,0 +1 @@
+Fetch unresolved comments for this branch's PR, then fix them

.claude/commands/repro-issue.md

@@ -0,0 +1 @@
+Repro issue $ARGUMENTS in a failing test

.gitignore

@@ -132,3 +132,4 @@ modules/drivers/*/.lsp/*
 
 .aider*
 /config.yml
+CLAUDE.local.md

CLAUDE.md

@@ -0,0 +1,111 @@
+# Metabase Development Guide
+
+## Autonomous Development Workflow
+
+- Do not attempt to read or edit files outside the project folder
+- Add failing tests first, then fix them
+- Work autonomously in small, testable increments
+- Run targeted tests, and lint continuously during development
+- Prioritize understanding existing patterns before implementing
+- Don't commit changes, leave it for the user to review and make commits
+
+## Quick Commands
+
+### JavaScript/TypeScript
+
+- **Lint:** `yarn lint-eslint`
+- **Test:** `yarn test-unit path/to/file.unit.spec.js` or `yarn test-unit -t "pattern"`
+- **Watch:** `yarn test-unit-watch path/to/file.unit.spec.js`
+- **Format:** `yarn prettier`
+- **Type Check:** `yarn type-check`
+
+### Clojure
+
+- **Lint:** `./bin/mage kondo [path]`
+- **Format:** `./bin/mage cljfmt-files [path]`
+- **Test file:** `clojure -X:dev:test :only namespace/test-name`
+
+### ClojureScript
+
+- **Test:** `yarn test-cljs`
+
+## Codebase
+
+### Frontend Technologies
+
+- **React** - Main frontend library
+- **Redux Toolkit** - State management library
+- **Mantine UI** - Customized UI component library, components are reexported from `metabase/ui`
+- **Styling** - Prefer Mantine style props; only when necessary, use CSS modules
+- **ECharts** - Visualization library for charts
+
+## Testing Conventions
+
+- Use isolated unit tests when the change is reasonable to test without complex dependencies
+- Tests must not mock internal details of components/functions being tested
+- Use helper factories like `createMockCard()` to create test objects
+- For more complex cases, write e2e Cypress tests in `e2e/test/scenarios/`
+
+### Mock Object Factories
+
+- Use mock factories to create test objects
+- Example: `createMockCard()` for Card objects
+- Located in `frontend/src/metabase-types/api/mocks/`
+
+```javascript
+import { createMockCard } from "metabase-types/api/mocks";
+
+const card = createMockCard({
+  id: 1,
+  name: "Test Card",
+  // Override other properties as needed
+});
+```
+
+### Clojure Testing
+
+- Tests are in `test/metabase/` matching the namespace structure of `src/`
+- Use `deftest` for test definitions
+- Use `testing` for organizing test groups
+- Use `is` for assertions
+
+```clojure
+(deftest my-function-test
+  (testing "should handle normal case"
+    (is (= expected (my-function input)))))
+```
+
+## Code Style Conventions
+
+### JavaScript/TypeScript
+
+- Using TypeScript for new code is preferred
+- Components should be in their own directories with related files
+- React functional components with hooks are preferred over class components
+- Use `.tsx` extension for React components with TypeScript
+- Use `.unit.spec.tsx` for component tests
+
+### Clojure/ClojureScript
+
+- Functions should have docstrings
+- Use `cljfmt` for consistent formatting
+- Use ClojureScript for frontend-facing code that needs to interoperate with the Clojure backend
+
+## Development Workflow Tips
+
+- Every bug fix or feature should include automated tests
+- The codebase uses a combination of Clojure (backend) and JavaScript/TypeScript (frontend)
+- Tests should be comprehensive and match the existing patterns
+- Use the provided factories for creating test objects
+- Follow existing patterns when adding new features
+
+## Application Entities
+
+- **Card/Question** - Saved questions/visualizations that can be displayed in dashboards
+- **Dashboard** - Collections of cards/visualizations
+- **Collection** - Organizational units for Cards, Dashboards, etc.
+- **Database** - Connected data sources
+- **Field** - Column in a database table
+- **Table** - Database table
+- **Segment** - Saved filters that can be applied to queries
+- **Metric** - Saved aggregations that can be used in queries

bin/claude-prompt

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+if [ $# -eq 0 ]; then
+    echo "Usage: claude-prompt <prompt>"
+    echo "  Launches Claude in non-interactive mode with Metabase-specific tools and the given prompt."
+    exit 1
+fi
+
+set -o xtrace
+
+claude -p "$(printf "%q " "$@")" --allowedTools "Bash(./bin/mage:*)" "Bash(clj-kondo:*)" "Bash(clojure:*)", "Bash(grep:*)" "Bash(ls:*)" "Bash(yarn lint:*)" "Bash(yarn test-unit:*)" "WebFetchTool(domain:github.com)" Edit

frontend/src/metabase/querying/viz-settings/utils/sync-viz-settings.ts

@@ -126,21 +126,30 @@ function syncColumns<T>({
   const oldNameByKey = Object.fromEntries(
     oldColumns.map((column) => [column.key, column.name]),
   );
+
+  // Track which column keys we've already processed to avoid duplicates
+  const processedKeys = new Set<string>();
+
   const remappedSettings = settings.reduce((settings: T[], setting) => {
     const oldName = getColumnName(setting);
     const oldKey = oldName && oldKeyByName[oldName];
     const newName = oldKey && newNameByKey[oldKey];
+
     if (!oldKey) {
       settings.push(setting);
     } else if (newName) {
+      // Mark this key as processed to avoid duplicates
+      processedKeys.add(oldKey);
       settings.push(setColumnName(setting, newName));
     }
     return settings;
   }, []);
+
   const remappedNames = new Set(remappedSettings.map(getColumnName));
   const addedSettings = newColumns
     .filter(
       (column) =>
+        !processedKeys.has(column.key) && // Skip columns we've already processed
         !oldNameByKey[column.key] &&
         !remappedNames.has(column.name) &&
         shouldCreateSetting(column),
@@ -163,8 +172,10 @@ function syncColumnNames({
   oldColumns,
   shouldCreateSetting,
 }: SyncColumnNamesOpts) {
-  return syncColumns({
-    settings,
+  // Use a Set to keep track of metric names we've already seen
+  const uniqueSettings = new Set(settings);
+  const result = syncColumns({
+    settings: Array.from(uniqueSettings),
     newColumns,
     oldColumns,
     getColumnName: (setting) => setting,
@@ -172,6 +183,9 @@ function syncColumnNames({
     createSetting: (column) => column.name,
     shouldCreateSetting,
   });
+
+  // Ensure no duplicates in the final result as well
+  return Array.from(new Set(result));
 }
 
 function syncTableColumns(
@@ -234,10 +248,13 @@ function syncGraphMetrics(
     return settings;
   }
 
+  // Remove any potential duplicates from graphMetrics before syncing
+  const uniqueGraphMetrics = Array.from(new Set(graphMetrics));
+
   return {
     ...settings,
     "graph.metrics": syncColumnNames({
-      settings: graphMetrics,
+      settings: uniqueGraphMetrics,
       newColumns,
       oldColumns,
       shouldCreateSetting: (column) => column.isAggregation,

frontend/src/metabase/querying/viz-settings/utils/sync-viz-settings.unit.spec.tsx

@@ -350,6 +350,27 @@ describe("syncVizSettings", () => {
         "graph.metrics": ["ID", "TAX"],
       });
     });
+
+    it("should handle duplicate metrics and ensure they are deduplicated when filter is removed", () => {
+      // This test simulates the issue reported in metabase#42447
+      const oldColumns: ColumnInfo[] = [
+        { name: "Category", key: "Category" },
+        { name: "count", key: "count", isAggregation: true },
+      ];
+      const newColumns: ColumnInfo[] = [
+        { name: "Category", key: "Category" },
+        { name: "count", key: "count", isAggregation: true },
+      ];
+      const oldSettings = createMockVisualizationSettings({
+        // Simulates the duplicated metrics that can happen when filter is removed
+        "graph.metrics": ["count", "count"],
+      });
+
+      const newSettings = syncVizSettings(oldSettings, newColumns, oldColumns);
+      expect(newSettings).toEqual({
+        "graph.metrics": ["count"],
+      });
+    });
   });
 
   describe("pivot_table", () => {