feat(compiler): defaults prop.value to true when it is null

Author: zhiyuanzmj

packages/compiler/src/transforms/transformElement.ts

@@ -1,4 +1,5 @@
 import {
+  createSimpleExpression,
   isValidHTMLNesting,
   type SimpleExpressionNode,
 } from '@vue/compiler-dom'
@@ -271,7 +272,7 @@ function transformProp(
       value:
         prop.value && prop.value.type === 'StringLiteral'
           ? resolveSimpleExpression(prop.value.value, true, prop.value.loc!)
-          : EMPTY_EXPRESSION,
+          : createSimpleExpression('true', false),
     }
   }
 

packages/compiler/test/transforms/__snapshots__/vBind.spec.ts.snap

@@ -1,5 +1,37 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
+exports[`compiler v-bind > .attr modifier 1`] = `
+"
+  const n0 = t0()
+  _renderEffect(() => _setAttr(n0, "foo-bar", id))
+  return n0
+"
+`;
+
+exports[`compiler v-bind > .camel modifier 1`] = `
+"
+  const n0 = t0()
+  _renderEffect(() => _setProp(n0, "fooBar", id))
+  return n0
+"
+`;
+
+exports[`compiler v-bind > .prop modifier 1`] = `
+"
+  const n0 = t0()
+  _renderEffect(() => _setDOMProp(n0, "fooBar", id))
+  return n0
+"
+`;
+
+exports[`compiler v-bind > no expression 1`] = `
+"
+  const n0 = t0()
+  _setProp(n0, "id", true)
+  return n0
+"
+`;
+
 exports[`compiler v-bind > with constant value 1`] = `
 "
   const n0 = t0()