From 75414243a3125e45ece79f8e52f8f32428c4d786 Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Wed, 26 Aug 2026 18:03:25 +0200
Subject: [PATCH 1/6] fix: check the example file for duplicate keys on scan

---
 .changeset/example-duplicates.md              |  5 ++
 docs/capabilities.md                          |  4 +-
 packages/cli/src/commands/scanUsage.ts        |  3 +
 packages/cli/src/config/types.ts              |  1 +
 packages/cli/src/services/printScanResult.ts  |  3 +-
 .../cli/src/services/processComparisonFile.ts | 52 ++++++++--------
 packages/cli/src/ui/shared/printDuplicates.ts |  4 +-
 .../cli/test/unit/commands/scanUsage.test.ts  | 61 +++++++++++++++++++
 .../unit/services/printScanResult.test.ts     | 22 +++++++
 .../services/processComparisonFile.test.ts    | 49 ++++++++++++---
 10 files changed, 167 insertions(+), 37 deletions(-)
 create mode 100644 .changeset/example-duplicates.md

diff --git a/.changeset/example-duplicates.md b/.changeset/example-duplicates.md
new file mode 100644
index 00000000..99366cea
--- /dev/null
+++ b/.changeset/example-duplicates.md
@@ -0,0 +1,5 @@
+---
+'dotenv-diff': patch
+---
+
+check the example file for duplicate keys on scan
diff --git a/docs/capabilities.md b/docs/capabilities.md
index 472e2d1f..7dffa0bf 100644
--- a/docs/capabilities.md
+++ b/docs/capabilities.md
@@ -84,7 +84,9 @@ Variables that are **defined in env files** but **never used** in the scanned co
 
 ### 3 Duplicate Keys
 
-Duplicate variable definitions inside env files (both main env and example env, when available).
+Duplicate variable definitions inside env files. Both the file being scanned and the example file documenting it are checked — the latter on every scan, against whichever example name applies (`.env.example`, `.env.sample`, `.env.template`, …), without needing `--example`.
+
+`--fix` only rewrites the env file, so duplicates reported in the example file stay reported after a fix.
 
 ### 4 Secret Detection
 
diff --git a/packages/cli/src/commands/scanUsage.ts b/packages/cli/src/commands/scanUsage.ts
index a8c9920b..459c06fc 100644
--- a/packages/cli/src/commands/scanUsage.ts
+++ b/packages/cli/src/commands/scanUsage.ts
@@ -110,6 +110,9 @@ export async function scanUsage(opts: ScanUsageOptions): Promise<ExitResult> {
     } else {
       scanResult = result.scanResult;
       comparedAgainst = result.comparedAgainst;
+      if (result.exampleFile) {
+        scanResult.exampleFile = result.exampleFile;
+      }
       fixApplied = result.fix.fixApplied;
       removedDuplicates = result.fix.removedDuplicates;
       fixedKeys = result.fix.addedEnv;
diff --git a/packages/cli/src/config/types.ts b/packages/cli/src/config/types.ts
index c6897ac9..2f20509b 100644
--- a/packages/cli/src/config/types.ts
+++ b/packages/cli/src/config/types.ts
@@ -289,6 +289,7 @@ export interface ScanResult {
   };
   frameworkWarnings?: FrameworkWarning[];
   exampleWarnings?: ExampleSecretWarning[];
+  exampleFile?: string;
   logged: EnvUsage[];
   uppercaseWarnings?: UppercaseWarning[];
   expireWarnings?: ExpireWarning[];
diff --git a/packages/cli/src/services/printScanResult.ts b/packages/cli/src/services/printScanResult.ts
index 5603a265..cd3bf47e 100644
--- a/packages/cli/src/services/printScanResult.ts
+++ b/packages/cli/src/services/printScanResult.ts
@@ -33,6 +33,7 @@ import { printListAll } from '../ui/scan/printListAll.js';
  * @param scanResult - The result of the scan.
  * @param opts - The scan options.
  * @param comparedAgainst - The file being compared against.
+ * @param fixContext - What `--fix` changed, when it ran.
  * @returns An object indicating whether to exit with an error.
  */
 export function printScanResult(
@@ -90,12 +91,12 @@ export function printScanResult(
   // Duplicates
   printDuplicates(
     comparedAgainst || DEFAULT_ENV_FILE,
-    'example file',
     scanResult.duplicates?.env ?? [],
     scanResult.duplicates?.example ?? [],
     isJson,
     opts.fix ?? false,
     opts.strict,
+    scanResult.exampleFile,
   );
 
   // Print potential secrets found
diff --git a/packages/cli/src/services/processComparisonFile.ts b/packages/cli/src/services/processComparisonFile.ts
index 048bebf4..b2c90439 100644
--- a/packages/cli/src/services/processComparisonFile.ts
+++ b/packages/cli/src/services/processComparisonFile.ts
@@ -163,7 +163,11 @@ export function processComparisonFile(
 
     // Find duplicates
     if (!opts.allowDuplicates) {
-      const duplicateResults = checkDuplicates(compareFile, opts);
+      const duplicateResults = checkDuplicates(
+        compareFile,
+        exampleFilePath,
+        opts,
+      );
       dupsEnv = duplicateResults.dupsEnv;
       dupsEx = duplicateResults.dupsEx;
     }
@@ -223,18 +227,16 @@ export function processComparisonFile(
         fix.addedEnv = result.addedEnv;
         fix.gitignoreUpdated = result.gitignoreUpdated;
 
-        // clear the issues that were fixed
+        // clear the issues that were fixed. `dupsEx` is not among them: the fix
+        // only rewrites the env file, so duplicates in the example file survive
+        // it and must still be reported.
         scanResult.missing = [];
         dupsEnv = [];
-        dupsEx = [];
       }
     }
 
-    // Keep duplicates for output if not fixed
-    if (
-      (dupsEnv.length > 0 || dupsEx.length > 0) &&
-      (!opts.fix || !fix.fixApplied)
-    ) {
+    // Keep the duplicates that were not fixed for output
+    if (dupsEnv.length > 0 || dupsEx.length > 0) {
       if (!scanResult.duplicates) scanResult.duplicates = {};
       if (dupsEnv.length > 0) scanResult.duplicates.env = dupsEnv;
       if (dupsEx.length > 0) scanResult.duplicates.example = dupsEx;
@@ -280,13 +282,22 @@ export function processComparisonFile(
 }
 
 /**
- * Check for duplicate keys in env and example files
+ * Check for duplicate keys in env and example files.
+ *
+ * The example file is taken from the caller rather than re-derived from
+ * `--example`, so it is checked whenever one exists beside the comparison file
+ * — the same reasoning as the drift check. Gating it on the flag meant the
+ * example was silently never checked in the common case of a plain
+ * `dotenv-diff scan`, even though a duplicated key there is exactly the kind of
+ * thing that misleads whoever copies the file.
  * @param compareFile - The file to compare against
+ * @param examplePath - Absolute path of the example file, or null when none was found
  * @param opts - Scan options
  * @returns Object containing duplicate keys in env and example files
  */
 function checkDuplicates(
   compareFile: ComparisonFile,
+  examplePath: string | null,
   opts: ScanUsageOptions,
 ): DuplicateResult {
   const isIgnored = (key: string) =>
@@ -297,21 +308,14 @@ function checkDuplicates(
     isIgnored(key),
   );
 
-  // Duplicates in example file
-  let dupsEx: Duplicate[] = [];
-
-  if (opts.examplePath) {
-    const examplePath = resolveFromCwd(opts.cwd, opts.examplePath);
-
-    const exampleIsDifferentFile =
-      fs.existsSync(examplePath) && examplePath !== compareFile.path;
-
-    if (exampleIsDifferentFile) {
-      dupsEx = findDuplicateKeys(examplePath).filter(({ key }) =>
-        isIgnored(key),
-      );
-    }
-  }
+  // Duplicates in example file. Skipped when it *is* the comparison file — a
+  // scan with no `.env` falls through to `.env.example`, and its duplicates are
+  // already reported as `dupsEnv`. `findDuplicateKeys` handles a path that does
+  // not exist, which an explicit `--example` may still point at.
+  const dupsEx: Duplicate[] =
+    examplePath && examplePath !== compareFile.path
+      ? findDuplicateKeys(examplePath).filter(({ key }) => isIgnored(key))
+      : [];
 
   return { dupsEnv, dupsEx } satisfies DuplicateResult;
 }
diff --git a/packages/cli/src/ui/shared/printDuplicates.ts b/packages/cli/src/ui/shared/printDuplicates.ts
index 2071e75a..9507f960 100644
--- a/packages/cli/src/ui/shared/printDuplicates.ts
+++ b/packages/cli/src/ui/shared/printDuplicates.ts
@@ -22,12 +22,12 @@ import type { Duplicate } from '../../config/types.js';
  */
 export function printDuplicates(
   envName: string,
-  exampleName: string,
   dEnv: Duplicate[],
   dEx: Duplicate[],
   json: boolean,
   fix: boolean = false,
   strict: boolean = false,
+  exampleName?: string,
 ): void {
   if (json) return;
 
@@ -45,7 +45,7 @@ export function printDuplicates(
     console.log(`${divider}`);
   }
 
-  if (dEx.length) {
+  if (dEx.length && exampleName) {
     console.log();
     console.log(`${indicator} ${header(`Duplicate keys in ${exampleName}`)}`);
     console.log(`${divider}`);
diff --git a/packages/cli/test/unit/commands/scanUsage.test.ts b/packages/cli/test/unit/commands/scanUsage.test.ts
index 5a8484b5..da80afcc 100644
--- a/packages/cli/test/unit/commands/scanUsage.test.ts
+++ b/packages/cli/test/unit/commands/scanUsage.test.ts
@@ -411,6 +411,67 @@ describe('scanUsage', () => {
     );
   });
 
+  it('attaches the resolved example file name onto the scan result', async () => {
+    // Carried through so findings about the example file can name it — a
+    // project may document itself with .env.sample rather than .env.example.
+    vi.mocked(determineComparisonFile).mockResolvedValue({
+      type: 'found',
+      file: { path: '/env/.env', name: '.env' },
+    });
+    vi.mocked(processComparisonFile).mockReturnValue({
+      scanResult: { ...baseScanResult },
+      comparedAgainst: '.env',
+      envVariables: {},
+      duplicatesFound: false,
+      dupsEnv: [],
+      dupsEx: [],
+      fix: {
+        fixApplied: false,
+        removedDuplicates: [],
+        addedEnv: [],
+        gitignoreUpdated: false,
+      },
+      exampleFile: '.env.sample',
+    } as ProcessComparisonResult);
+
+    await scanUsage({ ...baseOpts, json: false });
+
+    expect(printScanResult).toHaveBeenCalledWith(
+      expect.objectContaining({ exampleFile: '.env.sample' }),
+      expect.anything(),
+      expect.anything(),
+      expect.anything(),
+    );
+  });
+
+  it('leaves the example file name unset when no example file was resolved', async () => {
+    vi.mocked(determineComparisonFile).mockResolvedValue({
+      type: 'found',
+      file: { path: '/env/.env', name: '.env' },
+    });
+    vi.mocked(processComparisonFile).mockReturnValue({
+      scanResult: { ...baseScanResult },
+      comparedAgainst: '.env',
+      envVariables: {},
+      duplicatesFound: false,
+      dupsEnv: [],
+      dupsEx: [],
+      fix: {
+        fixApplied: false,
+        removedDuplicates: [],
+        addedEnv: [],
+        gitignoreUpdated: false,
+      },
+      exampleFile: undefined,
+    } as ProcessComparisonResult);
+
+    await scanUsage({ ...baseOpts, json: false });
+
+    expect(vi.mocked(printScanResult).mock.calls[0]?.[0]).not.toHaveProperty(
+      'exampleFile',
+    );
+  });
+
   it('sets frameworkWarnings on scanResult when frameworkValidator returns results', async () => {
     const { frameworkValidator } =
       await import('../../../src/core/frameworks/frameworkValidator.js');
diff --git a/packages/cli/test/unit/services/printScanResult.test.ts b/packages/cli/test/unit/services/printScanResult.test.ts
index 0c8b5a53..85d6dc9f 100644
--- a/packages/cli/test/unit/services/printScanResult.test.ts
+++ b/packages/cli/test/unit/services/printScanResult.test.ts
@@ -458,6 +458,28 @@ describe('printScanResult', () => {
     );
   });
 
+  it('names the example file in duplicates when the scan resolved one', () => {
+    printScanResult(
+      {
+        ...baseScanResult,
+        duplicates: { example: [{ key: 'EX_KEY', count: 2 }] },
+        exampleFile: '.env.sample',
+      },
+      baseOpts,
+      '.env',
+    );
+
+    expect(printDuplicates).toHaveBeenCalledWith(
+      '.env',
+      '.env.sample',
+      [],
+      [{ key: 'EX_KEY', count: 2 }],
+      false,
+      false,
+      undefined,
+    );
+  });
+
   it('does not print console log warning when logged is undefined', () => {
     printScanResult(
       {
diff --git a/packages/cli/test/unit/services/processComparisonFile.test.ts b/packages/cli/test/unit/services/processComparisonFile.test.ts
index 85be982a..6afaad88 100644
--- a/packages/cli/test/unit/services/processComparisonFile.test.ts
+++ b/packages/cli/test/unit/services/processComparisonFile.test.ts
@@ -254,15 +254,8 @@ describe('processComparisonFile', () => {
   });
 
   it('keeps duplicates when fix does not change anything', () => {
-    vi.mocked(applyFixes).mockReturnValueOnce({
-      changed: false,
-      result: {
-        removedDuplicates: [],
-        addedEnv: [],
-        gitignoreUpdated: false,
-      },
-    });
-
+    // `fix` is off, so applyFixes never runs — queueing a return value here
+    // would only leak into the next test that does enable it.
     const result = processComparisonFile(baseScanResult, compareFile, {
       ...baseOpts,
       allowDuplicates: false,
@@ -320,6 +313,44 @@ describe('processComparisonFile', () => {
     expect(result.exampleFull).toEqual({ A: '1', bKey: '2' });
   });
 
+  it('checks the example file for duplicates without the examplePath option', () => {
+    // Same reasoning as the drift check: the example beside the comparison file
+    // is checked whether or not --example was passed, so a duplicate there is
+    // not silently missed on a plain scan.
+    vi.mocked(findDuplicateKeys)
+      .mockReturnValueOnce([])
+      .mockReturnValueOnce([{ key: 'EX_KEY', count: 2 }]);
+
+    const result = processComparisonFile(
+      { ...baseScanResult, duplicates: {} },
+      compareFile,
+      { ...baseOpts, examplePath: undefined, allowDuplicates: false },
+    );
+
+    expect(findDuplicateKeys).toHaveBeenNthCalledWith(2, '/env/.env.example');
+    expect(result.dupsEx).toEqual([{ key: 'EX_KEY', count: 2 }]);
+  });
+
+  it('keeps example duplicates after a fix, which only rewrites the env file', () => {
+    vi.mocked(findDuplicateKeys)
+      .mockReturnValueOnce([{ key: 'A', count: 2 }])
+      .mockReturnValueOnce([{ key: 'EX_KEY', count: 2 }]);
+
+    const result = processComparisonFile(
+      { ...baseScanResult, duplicates: {} },
+      compareFile,
+      { ...baseOpts, fix: true, allowDuplicates: false },
+    );
+
+    expect(result.fix.fixApplied).toBe(true);
+    // The env file was deduplicated, the example file was never touched.
+    expect(result.dupsEnv).toHaveLength(0);
+    expect(result.scanResult.duplicates?.env).toBeUndefined();
+    expect(result.scanResult.duplicates?.example).toEqual([
+      { key: 'EX_KEY', count: 2 },
+    ]);
+  });
+
   it('skips example duplicate check when examplePath equals compareFile path', async () => {
     // resolveFromCwd returns the compareFile path → same file → skip
     const { resolveFromCwd } =

From 0fbfe20cc867f34faf61f6e98c6e35a73bd1cf43 Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Wed, 26 Aug 2026 18:32:04 +0200
Subject: [PATCH 2/6] chore: fix build

---
 packages/cli/src/commands/compare.ts          |  3 +-
 packages/cli/src/ui/shared/printDuplicates.ts |  2 +-
 .../cli/test/unit/commands/compare.test.ts    |  3 +-
 .../unit/ui/shared/printDuplicates.test.ts    | 35 ++++++++++++++++---
 4 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/packages/cli/src/commands/compare.ts b/packages/cli/src/commands/compare.ts
index 4af94500..188c2857 100644
--- a/packages/cli/src/commands/compare.ts
+++ b/packages/cli/src/commands/compare.ts
@@ -119,11 +119,12 @@ function processPair(
 
   printDuplicates(
     envName,
-    exampleName,
     dupsEnv,
     dupsEx,
     opts.json ?? false,
     opts.fix ?? false,
+    opts.strict ?? false,
+    exampleName,
   );
 
   const entry = compareJsonOutput({
diff --git a/packages/cli/src/ui/shared/printDuplicates.ts b/packages/cli/src/ui/shared/printDuplicates.ts
index 9507f960..5425159d 100644
--- a/packages/cli/src/ui/shared/printDuplicates.ts
+++ b/packages/cli/src/ui/shared/printDuplicates.ts
@@ -12,12 +12,12 @@ import type { Duplicate } from '../../config/types.js';
 /**
  * Prints duplicate keys found in the environment and example files.
  * @param envName The name of the environment file.
- * @param exampleName The name of the example file.
  * @param dEnv Array of duplicate keys in the environment file with their counts.
  * @param dEx Array of duplicate keys in the example file with their counts.
  * @param json Whether to output in JSON format.
  * @param fix Whether fix mode is enabled (skips printing duplicates as they will be fixed).
  * @param strict Whether strict mode is enabled.
+ * @param exampleName The name of the example file, when one was resolved.
  * @returns void
  */
 export function printDuplicates(
diff --git a/packages/cli/test/unit/commands/compare.test.ts b/packages/cli/test/unit/commands/compare.test.ts
index a41b8386..4cd6db06 100644
--- a/packages/cli/test/unit/commands/compare.test.ts
+++ b/packages/cli/test/unit/commands/compare.test.ts
@@ -885,11 +885,12 @@ describe('compareMany', () => {
     // printDuplicates receives false for both ?? args (lines 123-124)
     expect(mockPrintDuplicates).toHaveBeenCalledWith(
       '.env',
-      '.env.example',
       [],
       [],
       false,
       false,
+      false,
+      '.env.example',
     );
     // printIssues receives false for both ?? args (line 266)
     expect(mockPrintIssues).toHaveBeenCalledWith(
diff --git a/packages/cli/test/unit/ui/shared/printDuplicates.test.ts b/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
index 71de544a..31409844 100644
--- a/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
+++ b/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
@@ -24,18 +24,19 @@ describe('printDuplicates', () => {
   });
 
   it('does nothing when json is true', () => {
-    printDuplicates('.env', '.env.example', [], [], true);
+    printDuplicates('.env', [], [], true, false, false, '.env.example');
     expect(logSpy).not.toHaveBeenCalled();
   });
 
   it('does not print env duplicates when fix=true', () => {
     printDuplicates(
       '.env',
-      '.env.example',
       [{ key: 'A', count: 2 }],
       [],
       false,
       true,
+      false,
+      '.env.example',
     );
 
     expect(
@@ -46,7 +47,7 @@ describe('printDuplicates', () => {
   });
 
   it('does not print env duplicates when none exist', () => {
-    printDuplicates('.env', '.env.example', [], [], false, false);
+    printDuplicates('.env', [], [], false, false, false, '.env.example');
 
     expect(logSpy).not.toHaveBeenCalled();
   });
@@ -54,24 +55,48 @@ describe('printDuplicates', () => {
   it('prints both env and example duplicates together', () => {
     printDuplicates(
       '.env',
-      '.env.example',
       [{ key: 'A', count: 2 }],
       [{ key: 'B', count: 3 }],
       false,
+      false,
+      false,
+      '.env.example',
     );
 
     expect(logSpy).toHaveBeenCalled();
   });
 
+  it('names the example file that duplicates were found in', () => {
+    printDuplicates(
+      '.env',
+      [],
+      [{ key: 'B', count: 3 }],
+      false,
+      false,
+      false,
+      '.env.sample',
+    );
+
+    expect(logSpy).toHaveBeenCalledWith(
+      expect.stringContaining('H(Duplicate keys in .env.sample)'),
+    );
+  });
+
+  it('skips example duplicates when no example file was resolved', () => {
+    printDuplicates('.env', [], [{ key: 'B', count: 3 }], false);
+
+    expect(logSpy).not.toHaveBeenCalled();
+  });
+
   it('uses strict formatting when strict mode is enabled', () => {
     printDuplicates(
       '.env',
-      '.env.example',
       [{ key: 'A', count: 2 }],
       [{ key: 'B', count: 3 }],
       false,
       false,
       true,
+      '.env.example',
     );
 
     expect(logSpy).toHaveBeenCalledWith(

From 897ff7f50fdc5e061e3a1cb6852d2ea145a29db9 Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Thu, 27 Aug 2026 18:22:50 +0200
Subject: [PATCH 3/6] chore: refac

---
 packages/cli/src/commands/compare.ts          |  3 +--
 packages/cli/src/services/printScanResult.ts  |  2 +-
 packages/cli/src/ui/shared/printDuplicates.ts |  4 ++--
 .../cli/test/unit/commands/compare.test.ts    |  3 +--
 .../unit/ui/shared/printDuplicates.test.ts    | 22 +++++++++++++------
 5 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/packages/cli/src/commands/compare.ts b/packages/cli/src/commands/compare.ts
index 188c2857..4af94500 100644
--- a/packages/cli/src/commands/compare.ts
+++ b/packages/cli/src/commands/compare.ts
@@ -119,12 +119,11 @@ function processPair(
 
   printDuplicates(
     envName,
+    exampleName,
     dupsEnv,
     dupsEx,
     opts.json ?? false,
     opts.fix ?? false,
-    opts.strict ?? false,
-    exampleName,
   );
 
   const entry = compareJsonOutput({
diff --git a/packages/cli/src/services/printScanResult.ts b/packages/cli/src/services/printScanResult.ts
index cd3bf47e..5c64d679 100644
--- a/packages/cli/src/services/printScanResult.ts
+++ b/packages/cli/src/services/printScanResult.ts
@@ -91,12 +91,12 @@ export function printScanResult(
   // Duplicates
   printDuplicates(
     comparedAgainst || DEFAULT_ENV_FILE,
+    scanResult.exampleFile || 'example file',
     scanResult.duplicates?.env ?? [],
     scanResult.duplicates?.example ?? [],
     isJson,
     opts.fix ?? false,
     opts.strict,
-    scanResult.exampleFile,
   );
 
   // Print potential secrets found
diff --git a/packages/cli/src/ui/shared/printDuplicates.ts b/packages/cli/src/ui/shared/printDuplicates.ts
index 5425159d..758732f4 100644
--- a/packages/cli/src/ui/shared/printDuplicates.ts
+++ b/packages/cli/src/ui/shared/printDuplicates.ts
@@ -22,12 +22,12 @@ import type { Duplicate } from '../../config/types.js';
  */
 export function printDuplicates(
   envName: string,
+  exampleName: string,
   dEnv: Duplicate[],
   dEx: Duplicate[],
   json: boolean,
   fix: boolean = false,
   strict: boolean = false,
-  exampleName?: string,
 ): void {
   if (json) return;
 
@@ -45,7 +45,7 @@ export function printDuplicates(
     console.log(`${divider}`);
   }
 
-  if (dEx.length && exampleName) {
+  if (dEx.length) {
     console.log();
     console.log(`${indicator} ${header(`Duplicate keys in ${exampleName}`)}`);
     console.log(`${divider}`);
diff --git a/packages/cli/test/unit/commands/compare.test.ts b/packages/cli/test/unit/commands/compare.test.ts
index 4cd6db06..a41b8386 100644
--- a/packages/cli/test/unit/commands/compare.test.ts
+++ b/packages/cli/test/unit/commands/compare.test.ts
@@ -885,12 +885,11 @@ describe('compareMany', () => {
     // printDuplicates receives false for both ?? args (lines 123-124)
     expect(mockPrintDuplicates).toHaveBeenCalledWith(
       '.env',
+      '.env.example',
       [],
       [],
       false,
       false,
-      false,
-      '.env.example',
     );
     // printIssues receives false for both ?? args (line 266)
     expect(mockPrintIssues).toHaveBeenCalledWith(
diff --git a/packages/cli/test/unit/ui/shared/printDuplicates.test.ts b/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
index 31409844..7d9559e9 100644
--- a/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
+++ b/packages/cli/test/unit/ui/shared/printDuplicates.test.ts
@@ -24,19 +24,19 @@ describe('printDuplicates', () => {
   });
 
   it('does nothing when json is true', () => {
-    printDuplicates('.env', [], [], true, false, false, '.env.example');
+    printDuplicates('.env', '.env.example', [], [], true, false, false);
     expect(logSpy).not.toHaveBeenCalled();
   });
 
   it('does not print env duplicates when fix=true', () => {
     printDuplicates(
       '.env',
+      '.env.example',
       [{ key: 'A', count: 2 }],
       [],
       false,
       true,
       false,
-      '.env.example',
     );
 
     expect(
@@ -47,7 +47,7 @@ describe('printDuplicates', () => {
   });
 
   it('does not print env duplicates when none exist', () => {
-    printDuplicates('.env', [], [], false, false, false, '.env.example');
+    printDuplicates('.env', '.env.example', [], [], false, false, false);
 
     expect(logSpy).not.toHaveBeenCalled();
   });
@@ -55,12 +55,12 @@ describe('printDuplicates', () => {
   it('prints both env and example duplicates together', () => {
     printDuplicates(
       '.env',
+      '.env.example',
       [{ key: 'A', count: 2 }],
       [{ key: 'B', count: 3 }],
       false,
       false,
       false,
-      '.env.example',
     );
 
     expect(logSpy).toHaveBeenCalled();
@@ -69,12 +69,12 @@ describe('printDuplicates', () => {
   it('names the example file that duplicates were found in', () => {
     printDuplicates(
       '.env',
+      '.env.sample',
       [],
       [{ key: 'B', count: 3 }],
       false,
       false,
       false,
-      '.env.sample',
     );
 
     expect(logSpy).toHaveBeenCalledWith(
@@ -83,7 +83,15 @@ describe('printDuplicates', () => {
   });
 
   it('skips example duplicates when no example file was resolved', () => {
-    printDuplicates('.env', [], [{ key: 'B', count: 3 }], false);
+    printDuplicates(
+      '.env',
+      '',
+      [],
+      [{ key: 'B', count: 3 }],
+      false,
+      false,
+      false,
+    );
 
     expect(logSpy).not.toHaveBeenCalled();
   });
@@ -91,12 +99,12 @@ describe('printDuplicates', () => {
   it('uses strict formatting when strict mode is enabled', () => {
     printDuplicates(
       '.env',
+      '.env.example',
       [{ key: 'A', count: 2 }],
       [{ key: 'B', count: 3 }],
       false,
       false,
       true,
-      '.env.example',
     );
 
     expect(logSpy).toHaveBeenCalledWith(

From f5ff108d784444223ce5cb7b2ecc9429d9fecf84 Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Thu, 27 Aug 2026 18:26:01 +0200
Subject: [PATCH 4/6] chore: fix comment

---
 packages/cli/src/ui/shared/printDuplicates.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/cli/src/ui/shared/printDuplicates.ts b/packages/cli/src/ui/shared/printDuplicates.ts
index 758732f4..2071e75a 100644
--- a/packages/cli/src/ui/shared/printDuplicates.ts
+++ b/packages/cli/src/ui/shared/printDuplicates.ts
@@ -12,12 +12,12 @@ import type { Duplicate } from '../../config/types.js';
 /**
  * Prints duplicate keys found in the environment and example files.
  * @param envName The name of the environment file.
+ * @param exampleName The name of the example file.
  * @param dEnv Array of duplicate keys in the environment file with their counts.
  * @param dEx Array of duplicate keys in the example file with their counts.
  * @param json Whether to output in JSON format.
  * @param fix Whether fix mode is enabled (skips printing duplicates as they will be fixed).
  * @param strict Whether strict mode is enabled.
- * @param exampleName The name of the example file, when one was resolved.
  * @returns void
  */
 export function printDuplicates(

From f4d564dad346450252377b25d49b58b017550609 Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Thu, 27 Aug 2026 18:31:36 +0200
Subject: [PATCH 5/6] chore: fix test

---
 packages/cli/src/ui/shared/printDuplicates.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/cli/src/ui/shared/printDuplicates.ts b/packages/cli/src/ui/shared/printDuplicates.ts
index 2071e75a..25c5581c 100644
--- a/packages/cli/src/ui/shared/printDuplicates.ts
+++ b/packages/cli/src/ui/shared/printDuplicates.ts
@@ -45,7 +45,7 @@ export function printDuplicates(
     console.log(`${divider}`);
   }
 
-  if (dEx.length) {
+  if (dEx.length && exampleName) {
     console.log();
     console.log(`${indicator} ${header(`Duplicate keys in ${exampleName}`)}`);
     console.log(`${divider}`);

From 13c8c554f2e2a534b35ee92b966f7ac4bde2e16e Mon Sep 17 00:00:00 2001
From: Chrilleweb <cmn@dao.as>
Date: Thu, 27 Aug 2026 18:37:42 +0200
Subject: [PATCH 6/6] chore: fix winodws path

---
 .../cli/test/unit/services/processComparisonFile.test.ts   | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/cli/test/unit/services/processComparisonFile.test.ts b/packages/cli/test/unit/services/processComparisonFile.test.ts
index 6afaad88..35765109 100644
--- a/packages/cli/test/unit/services/processComparisonFile.test.ts
+++ b/packages/cli/test/unit/services/processComparisonFile.test.ts
@@ -71,6 +71,7 @@ vi.mock('../../../src/services/detectExampleDrift.js', () => ({
 }));
 
 import fs from 'fs';
+import path from 'path';
 import { processComparisonFile } from '../../../src/services/processComparisonFile.js';
 import { applyFixes } from '../../../src/services/fixEnv.js';
 import { parseEnvFile } from '../../../src/services/parseEnvFile.js';
@@ -327,7 +328,11 @@ describe('processComparisonFile', () => {
       { ...baseOpts, examplePath: undefined, allowDuplicates: false },
     );
 
-    expect(findDuplicateKeys).toHaveBeenNthCalledWith(2, '/env/.env.example');
+    // `path.join` in resolveExampleFile, so the separator is platform-specific.
+    expect(findDuplicateKeys).toHaveBeenNthCalledWith(
+      2,
+      path.join('/env', '.env.example'),
+    );
     expect(result.dupsEx).toEqual([{ key: 'EX_KEY', count: 2 }]);
   });