feat: support backend property hostcalls (#1002)

Author: Guy Bedford

documentation/docs/backend/Backend/Backend.mdx

@@ -197,8 +197,8 @@ async function app() {
     firstByteTimeout: 15000,
     betweenBytesTimeout: 10000,
     useSSL: true,
-    sslMinVersion: 1.3,
-    sslMaxVersion: 1.3,
+    tlsMinVersion: 1.3,
+    tlsMaxVersion: 1.3,
   });
   return fetch('https://www.fastly.com/', {
     backend // Here we are configuring this request to use the backend from above.
@@ -238,8 +238,8 @@ async function app() {
     firstByteTimeout: 15000,
     betweenBytesTimeout: 10000,
     useSSL: true,
-    sslMinVersion: 1.3,
-    sslMaxVersion: 1.3,
+    tlsMinVersion: 1.3,
+    tlsMaxVersion: 1.3,
   });
   return fetch('https://www.fastly.com/', {
     backend // Here we are configuring this request to use the backend from above.

documentation/docs/backend/Backend/health.mdx

@@ -7,6 +7,12 @@ pagination_prev: null
 
 # Backend.health()
 
+:::info
+
+This method is deprecated, use [`Backend.prototype.health`](./prototype/health.mdx) instead.
+
+:::
+
 The **`Backend.health()`** method returns a string representing the health of the given Backend instance.
 
 ## Syntax

documentation/docs/backend/Backend/prototype/betweenBytesTimeout.mdx

@@ -0,0 +1,18 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.betweenBytesTimeout
+
+The read-only **`betweenBytesTimeout`** property of a `Backend` instance is an integer number
+providing the between bytes timeout for this backend in milliseconds.
+
+When not set or in environments that do not support this property (such as Viceroy), `null`
+may be returned.
+
+## Value
+
+A `number` or `null`.

documentation/docs/backend/Backend/prototype/connectTimeout.mdx

@@ -0,0 +1,18 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.connectTimeout
+
+The read-only **`connectTimeout`** property of a `Backend` instance is an integer number
+providing the connect timeout for this backend in milliseconds.
+
+When not set or in environments that do not support this property (such as Viceroy), `null`
+may be returned.
+
+## Value
+
+A `number` or `null`.

documentation/docs/backend/Backend/prototype/firstByteTimeout.mdx

@@ -0,0 +1,18 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.firstByteTimeout
+
+The read-only **`firstByteTimeout`** property of a `Backend` instance is an integer number
+providing the first byte timeout for this backend in milliseconds.
+
+When not set or in environments that do not support this property (such as Viceroy), `null`
+may be returned.
+
+## Value
+
+A `number` or `null`.

documentation/docs/backend/Backend/prototype/health.mdx

@@ -0,0 +1,25 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.prototype.health()
+
+The **`Backend.prototype.health()`** method returns a string representing the health of the given Backend instance.
+
+## Syntax
+
+```js
+health()
+```
+
+### Return value
+
+A string representing the health of the specified Backend value.
+
+Possible values are:
+- `"healthy"` - The backend's health check has succeeded, indicating the backend is working as expected and should receive requests.
+- `"unhealthy"` - The backend's health check has failed, indicating the backend is not working as expected and should not receive requests.
+- `"unknown"` - The backend does not have a health check configured.

documentation/docs/backend/Backend/prototype/hostOverride.mdx

@@ -0,0 +1,15 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.hostOverride
+
+The read-only **`hostOverride`** property of a `Backend` instance is the host header
+override string used when sending requests to this backend.
+
+## Value
+
+A `string`.

documentation/docs/backend/Backend/prototype/httpKeepaliveTime.mdx

@@ -0,0 +1,15 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.httpKeepaliveTime
+
+The read-only **`httpKeepaliveTime`** property of a `Backend` instance is the HTTP keepalive
+time for this backend in milliseconds, or 0 if no keepalive is set.
+
+## Value
+
+A `number`.

documentation/docs/backend/Backend/prototype/isDynamic.mdx

@@ -0,0 +1,15 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.isDynamic
+
+The read-only **`isDynamic`** property of a `Backend` instance is a boolean
+indicating if the backend was dynamically created for this service.
+
+## Value
+
+A `boolean`.

documentation/docs/backend/Backend/prototype/isSSL.mdx

@@ -0,0 +1,15 @@
+---
+hide_title: false
+hide_table_of_contents: false
+pagination_next: null
+pagination_prev: null
+---
+
+# Backend.isSSL
+
+The read-only **`isSSL`** property of a `Backend` instance is a boolean
+indicating if the backend is using an SSL connection.
+
+## Value
+
+A `boolean`.