init-exe/init-lib template: fix use of install() and run()

And while we're at it, make the unit tests be actually executed.

lib/init-exe/build.zig

@@ -27,12 +27,12 @@ pub fn build(b: *std.Build) void {
     // This declares intent for the executable to be installed into the
     // standard location when the user invokes the "install" step (the default
     // step when running `zig build`).
-    exe.install();
+    b.installArtifact(exe);
 
     // This *creates* a RunStep in the build graph, to be executed when another
     // step is evaluated that depends on it. The next line below will establish
     // such a dependency.
-    const run_cmd = exe.run();
+    const run_cmd = b.addRunArtifact(exe);
 
     // By making the run step depend on the install step, it will be run from the
     // installation directory rather than directly from within the cache directory.
@@ -52,16 +52,19 @@ pub fn build(b: *std.Build) void {
     const run_step = b.step("run", "Run the app");
     run_step.dependOn(&run_cmd.step);
 
-    // Creates a step for unit testing.
-    const exe_tests = b.addTest(.{
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const unit_tests = b.addTest(.{
         .root_source_file = .{ .path = "src/main.zig" },
         .target = target,
         .optimize = optimize,
     });
 
+    const run_unit_tests = b.addRunArtifact(unit_tests);
+
     // Similar to creating the run step earlier, this exposes a `test` step to
     // the `zig build --help` menu, providing a way for the user to request
     // running the unit tests.
     const test_step = b.step("test", "Run unit tests");
-    test_step.dependOn(&exe_tests.step);
+    test_step.dependOn(&run_unit_tests.step);
 }

lib/init-lib/build.zig

@@ -27,18 +27,21 @@ pub fn build(b: *std.Build) void {
     // This declares intent for the library to be installed into the standard
     // location when the user invokes the "install" step (the default step when
     // running `zig build`).
-    lib.install();
+    b.installArtifact(lib);
 
-    // Creates a step for unit testing.
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
     const main_tests = b.addTest(.{
         .root_source_file = .{ .path = "src/main.zig" },
         .target = target,
         .optimize = optimize,
     });
 
+    const run_main_tests = b.addRunArtifact(main_tests);
+
     // This creates a build step. It will be visible in the `zig build --help` menu,
     // and can be selected like this: `zig build test`
     // This will evaluate the `test` step rather than the default, which is "install".
     const test_step = b.step("test", "Run library tests");
-    test_step.dependOn(&main_tests.step);
+    test_step.dependOn(&run_main_tests.step);
 }