From 8f4f6b7503ad8bc1565755b9352ff42df135f713 Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Tue, 19 Jul 2022 15:46:13 +0800
Subject: [PATCH] fix(core): only deep merge theme by one level, fix #1298

---
 packages/core/src/config.ts                 |  2 +-
 packages/core/src/utils/object.ts           |  6 ++---
 test/__snapshots__/preset-mini.test.ts.snap |  8 ++++++
 test/preset-mini.test.ts                    | 27 +++++++++++++++++++++
 4 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/config.ts b/packages/core/src/config.ts
index cec533db74..5ca028c3e5 100644
--- a/packages/core/src/config.ts
+++ b/packages/core/src/config.ts
@@ -79,7 +79,7 @@ export function resolveConfig(
   const theme = clone([
     ...sortedPresets.map(p => p.theme || {}),
     config.theme || {},
-  ].reduce((a, p) => mergeDeep(a, p), {}))
+  ].reduce((a, p) => mergeDeep(a, p, 1), {}))
 
   ;(mergePresets('extendTheme') as ThemeExtender<any>[]).forEach(extendTheme => extendTheme(theme))
 
diff --git a/packages/core/src/utils/object.ts b/packages/core/src/utils/object.ts
index c468e4dd91..9a5b0ca4b7 100644
--- a/packages/core/src/utils/object.ts
+++ b/packages/core/src/utils/object.ts
@@ -47,7 +47,7 @@ export function isObject(item: any): item is Record<string, any> {
   return (item && typeof item === 'object' && !Array.isArray(item))
 }
 
-export function mergeDeep<T>(original: T, patch: DeepPartial<T>): T {
+export function mergeDeep<T>(original: T, patch: DeepPartial<T>, level = Infinity): T {
   const o = original as any
   const p = patch as any
 
@@ -60,8 +60,8 @@ export function mergeDeep<T>(original: T, patch: DeepPartial<T>): T {
   const output = { ...o }
   if (isObject(o) && isObject(p)) {
     Object.keys(p).forEach((key) => {
-      if ((isObject(o[key]) && isObject(p[key])) || (Array.isArray(o[key]) && Array.isArray(p[key])))
-        output[key] = mergeDeep(o[key], p[key])
+      if (level > 0 && ((isObject(o[key]) && isObject(p[key])) || (Array.isArray(o[key]) && Array.isArray(p[key]))))
+        output[key] = mergeDeep(o[key], p[key], level - 1)
       else
         Object.assign(output, { [key]: p[key] })
     })
diff --git a/test/__snapshots__/preset-mini.test.ts.snap b/test/__snapshots__/preset-mini.test.ts.snap
index 3690913c2f..b611885871 100644
--- a/test/__snapshots__/preset-mini.test.ts.snap
+++ b/test/__snapshots__/preset-mini.test.ts.snap
@@ -17,6 +17,14 @@ exports[`preset-mini > dark customizing selector 1`] = `
 [data-mode=\\"light\\"] .light\\\\:disabled\\\\:w-full:disabled{width:100%;}"
 `;
 
+exports[`preset-mini > fontSize theme 1`] = `
+"/* layer: default */
+.text-lg{font-size:3rem;line-height:1.5em;}
+.text-medium{font-size:2rem;line-height:1.5em;}
+.text-small{font-size:1rem;line-height:1;}
+.text-xs{font-size:2rem;line-height:1;}"
+`;
+
 exports[`preset-mini > nested theme colors 1`] = `
 "/* layer: default */
 .bg-a-b-c{--un-bg-opacity:1;background-color:rgba(81,69,67,var(--un-bg-opacity));}
diff --git a/test/preset-mini.test.ts b/test/preset-mini.test.ts
index 89558da446..f490b92d45 100644
--- a/test/preset-mini.test.ts
+++ b/test/preset-mini.test.ts
@@ -111,4 +111,31 @@ describe('preset-mini', () => {
     expect(css).toMatchInlineSnapshot('""')
     expect([...matched]).toEqual([])
   })
+
+  test('fontSize theme', async () => {
+    const uno = createGenerator({
+      presets: [
+        presetMini(),
+      ],
+      theme: {
+        fontSize: {
+          small: '1rem',
+          medium: ['2rem', '1.5em'],
+          xs: '2rem',
+          lg: ['3rem', '1.5em'],
+        },
+      },
+    })
+
+    const { css } = await uno.generate([
+      'text-small',
+      'text-medium',
+      'text-xs',
+      'text-lg',
+    ].join(' '), { preflights: false })
+
+    // @ts-expect-error types
+    expect(uno.config.theme.fontSize.lg).toEqual(['3rem', '1.5em'])
+    expect(css).toMatchSnapshot()
+  })
 })