feat: show count of each mismatching version for a dependency

Helpful to see the number of times each version has been seen across the workspace, especially when deciding what the correct version to use is.

Author: bmish

README.md

@@ -32,8 +32,8 @@ If there are no dependency mismatches, the program will exit with success.
 If there are any dependency mismatches, the program will exit with failure and output the mismatching versions:
 
 ```pt
-eslint has more than one version: ^7.0.0, ^7.1.0
-sinon has more than one version: ^1.17.7, ^9.0.3
+eslint has more than one version: ^7.0.0 (1 usage), ^7.1.0 (5 usages)
+sinon has more than one version: ^1.17.7 (1 usage), ^9.0.3 (3 usages)
 ```
 
 ## Options

lib/dependency-versions.ts

@@ -8,7 +8,10 @@ export type DependenciesToVersionsSeen = Map<
 
 export type MismatchingDependencyVersions = Array<{
   dependency: string;
-  versions: string[];
+  versions: {
+    version: string;
+    count: number;
+  }[];
 }>;
 
 /**
@@ -118,8 +121,13 @@ export function calculateMismatchingVersions(
       const uniqueVersions = [
         ...new Set(versionList.map((obj) => obj.version)),
       ].sort();
+      const uniqueVersionsWithCounts = uniqueVersions.map((uniqueVersion) => ({
+        version: uniqueVersion,
+        count: versionList.filter((obj) => obj.version === uniqueVersion)
+          .length,
+      }));
       if (uniqueVersions.length > 1) {
-        return { dependency, versions: uniqueVersions };
+        return { dependency, versions: uniqueVersionsWithCounts };
       }
 
       return undefined;

lib/output.ts

@@ -5,6 +5,17 @@ export function mismatchingVersionsToOutputLines(
 ): string[] {
   return mismatchingDependencyVersions.map(
     (obj) =>
-      `${obj.dependency} has more than one version: ${obj.versions.join(', ')}`
+      `${obj.dependency} has more than one version: ${obj.versions
+        .map(
+          (versionObj) =>
+            `${versionObj.version} (${versionObj.count} ${pluralizeUsage(
+              versionObj.count
+            )})`
+        )
+        .join(', ')}`
   );
 }
+
+function pluralizeUsage(count: number) {
+  return count === 1 ? 'usage' : 'usages';
+}

test/fixtures/inconsistent-versions/scope1/package3/package.json

@@ -0,0 +1,5 @@
+{
+    "dependencies": {
+      "foo": "1.2.0"
+    }
+}

test/lib/dependency-versions.ts

@@ -28,11 +28,29 @@ describe('Utils | dependency-versions', function () {
       deepStrictEqual(calculateMismatchingVersions(dependencyVersions), [
         {
           dependency: 'baz',
-          versions: ['^7.8.9', '^8.0.0'],
+          versions: [
+            {
+              count: 1,
+              version: '^7.8.9',
+            },
+            {
+              count: 1,
+              version: '^8.0.0',
+            },
+          ],
         },
         {
           dependency: 'foo',
-          versions: ['1.2.0', '1.3.0'],
+          versions: [
+            {
+              count: 2,
+              version: '1.2.0',
+            },
+            {
+              count: 1,
+              version: '1.3.0',
+            },
+          ],
         },
       ]);
     });
@@ -46,7 +64,16 @@ describe('Utils | dependency-versions', function () {
         [
           {
             dependency: 'foo',
-            versions: ['1.2.0', '1.3.0'],
+            versions: [
+              {
+                count: 2,
+                version: '1.2.0',
+              },
+              {
+                count: 1,
+                version: '1.3.0',
+              },
+            ],
           },
         ]
       );

test/lib/output.ts

@@ -7,12 +7,24 @@ describe('Utils | output', function () {
     it('behaves correctly', function () {
       deepStrictEqual(
         mismatchingVersionsToOutputLines([
-          { dependency: 'foo', versions: ['1.2.3', '4.5.6'] },
-          { dependency: 'bar', versions: ['1.4.0', '2.0.0'] },
+          {
+            dependency: 'foo',
+            versions: [
+              { version: '1.2.3', count: 1 },
+              { version: '4.5.6', count: 2 },
+            ],
+          },
+          {
+            dependency: 'bar',
+            versions: [
+              { version: '1.4.0', count: 3 },
+              { version: '2.0.0', count: 4 },
+            ],
+          },
         ]),
         [
-          'foo has more than one version: 1.2.3, 4.5.6',
-          'bar has more than one version: 1.4.0, 2.0.0',
+          'foo has more than one version: 1.2.3 (1 usage), 4.5.6 (2 usages)',
+          'bar has more than one version: 1.4.0 (3 usages), 2.0.0 (4 usages)',
         ]
       );
     });