fix: keep dry-run output valid json

lib/utils/reify-output.js

@@ -44,7 +44,8 @@ const reifyOutput = (npm, arb, extras = {}) => {
   }
 
   if (diff) {
-    const showDiff = npm.config.get('dry-run') || npm.config.get('long')
+    const showDiff = !npm.flatOptions.json &&
+      (npm.config.get('dry-run') || npm.config.get('long'))
     const chalk = npm.chalk
 
     depth({

test/lib/utils/reify-output.js

@@ -440,6 +440,53 @@ t.test('prints dedupe difference on dry-run', async t => {
   t.matchSnapshot(out, 'diff table')
 })
 
+t.test('prints only json for dry-run and long', async t => {
+  for (const flag of ['dry-run', 'long']) {
+    await t.test(flag, async t => {
+      const out = await mockReify(t, {
+        actualTree: {
+          inventory: {
+            has: () => true,
+          },
+          children: [],
+        },
+        diff: {
+          children: [
+            {
+              action: 'ADD',
+              ideal: {
+                path: 'test/foo',
+                name: 'foo',
+                package: { version: '1.0.0' },
+              },
+            },
+          ],
+        },
+      }, {
+        [flag]: true,
+        json: true,
+      })
+
+      t.strictSame(JSON.parse(out), {
+        add: [
+          {
+            name: 'foo',
+            version: '1.0.0',
+            path: 'test/foo',
+          },
+        ],
+        added: 1,
+        audited: 0,
+        change: [],
+        changed: 0,
+        funding: 0,
+        remove: [],
+        removed: 0,
+      })
+    })
+  }
+})
+
 t.test('prints dedupe difference on long', async t => {
   const mock = {
     actualTree: {