docs: improve document for setChecked(), setSelected() and setValue() (#728)

Author: 38elements

Diff for: docs/api/wrapper/setChecked.md

@@ -1,9 +1,9 @@
-## setChecked(value)
+## setChecked(checked)
 
-Sets the value of a radio or checkbox `<input>`.
+Sets checked value for input element of type checkbox or radio and updates `v-model` bound data.
 
 - **Arguments:**
-  - `{Boolean} selected`
+  - `{Boolean} checked (default: true)`
 
 - **Example:**
 
@@ -16,3 +16,14 @@ const option = wrapper.find('input[type="radio"]')
 option.setChecked()
 ```
 
+- **Note:**
+
+When you try to set the value to state via `v-model` by `radioInput.element.checked = true; radioInput.trigger('input')`, `v-model` is not triggered. `v-model` is triggered by `change` event.
+
+`checkboxInput.setChecked(checked)` is an alias of the following code.
+
+```js
+checkboxInput.element.checked = checked
+checkboxInput.trigger('click')
+checkboxInput.trigger('change')
+```

Diff for: docs/api/wrapper/setSelected.md

@@ -1,9 +1,6 @@
-## setSelected(value)
+## setSelected()
 
-Sets a specified `<option>` as selected in a `<select>`.
-
-- **Arguments:**
-  - `{Boolean} selected`
+Selects an option element and updates `v-model` bound data.
 
 - **Example:**
 
@@ -15,5 +12,15 @@ const wrapper = shallowMount(Foo)
 const options = wrapper.find('select').findAll('option')
 
 options.at(1).setSelected()
-expect(wrapper.text()).to.contain('option1')
+```
+
+- **Note:**
+
+When you try to set the value to state via `v-model` by `option.element.selected = true; parentSelect.trigger('input')`, `v-model` is not triggered. `v-model` is triggered by `change` event.
+
+`option.setSelected()` is an alias of the following code.
+
+```js
+option.element.selected = true
+parentSelect.trigger('change')
 ```

Diff for: docs/api/wrapper/setValue.md

@@ -1,6 +1,6 @@
 ## setValue(value)
 
-Sets the value of a text `<input>`.
+Sets value of a text-control input element and updates `v-model` bound data.
 
 - **Arguments:**
   - `{String} value`
@@ -15,3 +15,12 @@ const wrapper = mount(Foo)
 const input = wrapper.find('input[type="text"]')
 input.setValue('some value')
 ```
+
+- **Note:**
+
+`textInput.setValue(value)` is an alias of the following code.
+
+```js
+textInput.element.value = value
+textInput.trigger('input')
+```