* chore: add @types/node as an explicit dependency
As `tsconfig.json` references it, it should be listed in the dependencies.
It currently uses an older version: this commit also bumps to the latest v12 version, and fixes a typing issue.
* fix(reactivity): remove Symbol.observable
`Symbol.observable` is brought by `@types/node@12` and is not a "well-known" typescript symbol https://www.typescriptlang.org/docs/handbook/symbols.html that can be find in lib.es20xx like the others. It has been removed in `@types/node@v13`.
It means that an application using vue@3.0.0-alpha.13 does not compile unless it explicitely adds `@types/node@v12` as a dependency and `node` in its own tsconfig types.
BREAKING CHANGE: Reactivity APIs adjustments:
- `readonly` is now non-tracking if called on plain objects.
`lock` and `unlock` have been removed. A `readonly` proxy can no
longer be directly mutated. However, it can still wrap an already
reactive object and track changes to the source reactive object.
- `isReactive` now only returns true for proxies created by `reactive`,
or a `readonly` proxy that wraps a `reactive` proxy.
- A new utility `isProxy` is introduced, which returns true for both
reactive or readonly proxies.
- `markNonReactive` has been renamed to `markRaw`.
BREAKING CHANGE: this.$emit() and setupContext.emit() no longer
return values. For logic that relies on return value of listeners,
the listener should be declared as an `onXXX` prop and be called
directly. This still allows the parent component to pass in
a handler using `v-on`, since `v-on:foo` internally compiles
to `onFoo`.
ref: https://github.com/vuejs/rfcs/pull/16
BREAKING CHANGE: compiler options have been adjusted.
- new option `decodeEntities` is added.
- `namedCharacterReferences` option has been removed.
- `maxCRNameLength` option has been rmeoved.
BREAKING CHANGE: `retryWhen` and `maxRetries` options for
`defineAsyncComponent` has been replaced by the more flexible `onError`
option, per https://github.com/vuejs/rfcs/pull/148
