test: add spread tests for env-injector extension

- add: spread test:
  * hello.c: application which consumes env variables
  * task.yaml: Tests to verify env-injector functionality

Signed-off-by: Lincoln Wallace <[email protected]>

tests/spread/extensions/env-injector/task.yaml

@@ -0,0 +1,53 @@
+summary: Build and run a basic hello-world snap using extensions
+
+systems:
+  - ubuntu-24.04
+
+environment:
+
+  SNAPCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS: "1"
+  SNAP_DIR: ../snaps/env-injector-hello
+  SNAP: env-injector-hello
+
+prepare: |
+
+  #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
+  . "$TOOLS_DIR/snapcraft-yaml.sh"
+  set_base "$SNAP_DIR/snap/snapcraft.yaml"
+
+restore: |
+
+  cd "$SNAP_DIR"
+  snapcraft clean
+  rm -f ./*.snap
+  rm -rf ./squashfs-root
+  #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
+  . "$TOOLS_DIR/snapcraft-yaml.sh"
+  restore_yaml "snap/snapcraft.yaml"
+
+execute: |
+
+  cd "$SNAP_DIR"
+  snapcraft
+
+  unsquashfs "${SNAP}"_1.0_*.snap
+
+  # Check that the env-exporter program is present
+  [ -f squashfs-root/bin/command-chain/env-exporter ]
+  
+  # Check that the hello command is present
+  [ -f squashfs-root/usr/local/bin/hello ]
+
+  snap install "${SNAP}"_1.0_*.snap --dangerous
+
+  # Create envfile
+  echo 'HELLO_WORLD="Hello, World"' >> envfile.env
+
+  # Set env vars: Global, App specific, and envfile
+  snap set env-injector-hello env.hello="Hello"
+  snap set env-injector-hello apps.hello.env.world="World"
+  snap set env-injector-hello envfile="${SNAP_DIR}"/enfile.env
+
+  # Run the hello command
+  env-injector-hello.hello
+

tests/spread/extensions/snaps/env-injector-hello/CMakeLists.txt

@@ -0,0 +1,4 @@
+cmake_minimum_required(VERSION 3.5)
+project(hello C)
+add_executable(hello hello.c)
+install(TARGETS hello RUNTIME DESTINATION bin)

tests/spread/extensions/snaps/env-injector-hello/hello.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char const *argv[]) {
+    const char *envs[] = {
+        "HELLO",        // This is set globally
+        "WORLD",        // This is set for the app
+        "HELLO_WORLD",  // This is set from env file
+    };
+
+    const char *expected[] = {
+        "Hello",
+        "World",
+        "Hello World",
+    };
+
+    int num_envs = sizeof(envs) / sizeof(envs[0]);
+
+    for (int i = 0; i < num_envs; ++i) {
+        const char *env = getenv(envs[i]);
+
+        if (env == NULL) {
+            fprintf(stderr, "\n[ERROR] Env. variable %s is not set.\n", envs[i]);
+            return 1;
+        }
+
+        if (strcmp(env, expected[i]) != 0) {
+            fprintf(stderr, "\n[ERROR] Env. variable %s isn't set to the expected value.\n", envs[i]);
+            fprintf(stderr, "Expected: %s\n", expected[i]);
+            fprintf(stderr, "Got: %s\n", env);
+            return 1;
+        }
+    }
+
+    return 0;
+}

tests/spread/extensions/snaps/env-injector-hello/snap/snapcraft.yaml

@@ -0,0 +1,18 @@
+name: env-injector-hello
+version: "1.0"
+summary: test the env-injector extension
+description: This is a basic snap for testing env-injector extension
+
+grade: devel
+base: core24
+confinement: strict
+
+apps:
+  env-hello:
+    command: usr/local/bin/hello
+    extensions: [ env-injector ]
+
+parts:
+  hello:
+    plugin: cmake
+    source: .

tests/unit/commands/test_list_extensions.py

@@ -38,6 +38,7 @@ def test_command(emitter, command):
             """\
         Extension name          Supported bases
         ----------------------  ----------------------
+        env-injector            core24
         fake-extension          core22, core24
         flutter-beta            core18
         flutter-dev             core18

tests/unit/extensions/test_registry.py

@@ -24,6 +24,7 @@
 @pytest.mark.usefixtures("fake_extension_experimental")
 def test_get_extension_names():
     assert extensions.get_extension_names() == [
+        "env-injector",
         "gnome",
         "ros2-humble",
         "ros2-humble-ros-core",