Add pg_validate_extupgrade config

.github/docker/Dockerfile

@@ -33,6 +33,13 @@ RUN apt-get update && apt-get install -y \
     postgresql-server-dev-${POSTGRESQL} \
     postgresql-${POSTGRESQL}
 
+# Setup pg_validate_extupgrade
+RUN apt-get update && apt install -y cargo
+RUN git clone https://github.com/rjuju/pg_validate_extupgrade.git
+WORKDIR pg_validate_extupgrade
+RUN cargo build --release
+RUN cp ./target/release/pg_validate_extupgrade /usr/bin/
+
 # Set workdir
 WORKDIR /github/workspace
 

h3/sql/updates/h3--4.0.0--unreleased.sql

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2022 Bytes & Brains
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION h3 UPDATE TO 'unreleased'" to load this file. \quit
+
+-- no changes

pg_validate_extupgrade.toml

@@ -0,0 +1,6 @@
+extname = 'h3'
+from = '3.7.2'
+to = '4.0.0'
+extra_queries = [
+    "SELECT COUNT(*) FROM pg_class WHERE relname = 'dump_0'"
+]