Fix examples (#1093)

* ci: verify all examples build.

Using examples/showcase masked breakages in multiple examples.

* examples/future: add change implementation.

* examples/minimal: add change implementation.

* examples/nested_list: add change implementation.

* ci: add block lists to skip some examples.

ci/check_examples.sh

@@ -3,19 +3,36 @@ echo "$(rustup default)" | grep -q "1.39.0"
 emscripten_supported=$?
 set -euxo pipefail # https://vaneyckt.io/posts/safer_bash_scripts_with_set_euxo_pipefail/
 
-# Showcase includes all other examples
+# Some examples are known not to work with some builds, i.e. futures with the
-cd examples/showcase
+# std_web feature.  Other items in the examples/ directory are helpers, i.e.
+# pub_sub and server.  These block lists allow us to exempt some examples but
+# default opt-in any new examples to CI testing.
+COMMON_SKIP_EXAMPLES="examples/static examples/pub_sub examples/server \
+  examples/target examples/web_sys examples/std_web"
+STD_WEB_SKIP_EXAMPLES="${COMMON_SKIP_EXAMPLES:?} examples/futures"
+WEB_SYS_SKIP_EXAMPLES="${COMMON_SKIP_EXAMPLES:?}"
+
+# Make sure all examples are buildable with stdweb and web-sys.
+for ex in $(find examples -maxdepth 1 -mindepth 1 -type d); do
+  pushd $ex
 
   # TODO Can't build some demos with release, need fix
 
   if [ "$emscripten_supported" == "0" ]; then
+    if [[ ! " ${STD_WEB_SKIP_EXAMPLES[@]} " =~ " ${ex} " ]]; then
       # TODO - Emscripten builds are broken on rustc > 1.39.0
       cargo web build --target asmjs-unknown-emscripten --features std_web
       cargo web build --target wasm32-unknown-emscripten --features std_web
     fi
+  fi
 
+  if [[ ! " ${STD_WEB_SKIP_EXAMPLES[@]} " =~ " ${ex} " ]]; then
     cargo web build --target wasm32-unknown-unknown --features std_web
+  fi
+  if [[ ! " ${WEB_SYS_SKIP_EXAMPLES[@]} " =~ " ${ex} " ]]; then
     cargo build --target wasm32-unknown-unknown --features web_sys
+  fi
 
   # Reset cwd
-cd ../..
+  popd
+done

examples/futures/src/lib.rs

@@ -101,6 +101,10 @@ impl Component for Model {
         }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, msg: Self::Message) -> ShouldRender {
         match msg {
             Msg::SetMarkdownFetchState(fetch_state) => {

examples/minimal/src/lib.rs

@@ -16,6 +16,10 @@ impl Component for Model {
         Model { link }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, msg: Self::Message) -> ShouldRender {
         match msg {
             Msg::Click => {}

examples/nested_list/src/app.rs

@@ -24,6 +24,10 @@ impl Component for App {
         }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, msg: Self::Message) -> ShouldRender {
         match msg {
             Msg::Hover(hovered) => self.hovered = hovered,

examples/nested_list/src/header.rs

@@ -21,6 +21,10 @@ impl Component for ListHeader {
         ListHeader { props }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, _: Self::Message) -> ShouldRender {
         false
     }

examples/nested_list/src/item.rs

@@ -24,6 +24,10 @@ impl Component for ListItem {
         ListItem { props }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, _msg: Self::Message) -> ShouldRender {
         false
     }

examples/nested_list/src/list.rs

@@ -56,6 +56,10 @@ impl Component for List {
         }
     }
 
+    fn change(&mut self, _: Self::Properties) -> bool {
+        false
+    }
+
     fn update(&mut self, msg: Self::Message) -> ShouldRender {
         match msg {
             Msg::HeaderClick => {
@@ -122,8 +126,10 @@ where
 impl Into<VNode> for ListVariant {
     fn into(self) -> VNode {
         match self.props {
-            Variants::Header(props) => VComp::new::<ListHeader>(props, NodeRef::default()).into(),
+            Variants::Header(props) => {
-            Variants::Item(props) => VComp::new::<ListItem>(props, NodeRef::default()).into(),
+                VComp::new::<ListHeader>(props, NodeRef::default(), None).into()
+            }
+            Variants::Item(props) => VComp::new::<ListItem>(props, NodeRef::default(), None).into(),
         }
     }
 }