add library for stuff

build.zig

@@ -24,11 +24,25 @@ pub fn build(b: *std.Build) void {
         .optimize = optimize,
     });
 
+    const lib = b.addSharedLibrary(.{
+        .name = "faas-proxy-sample-lib",
+        // In this case the main source file is merely a path, however, in more
+        // complicated build scripts, this could be a generated file.
+        .root_source_file = .{ .path = "src/main-lib.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+
     // 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`).
     b.installArtifact(exe);
 
+    // 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`).
+    b.installArtifact(lib);
+
     // 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.
@@ -46,25 +60,26 @@ pub fn build(b: *std.Build) void {
         run_cmd.addArgs(args);
     }
 
-    // This creates a build step. It will be visible in the `zig build --help` menu,
-    // and can be selected like this: `zig build run`
-    // This will evaluate the `run` step rather than the default, which is "install".
-    const run_step = b.step("run", "Run the app");
-    run_step.dependOn(&run_cmd.step);
-
     // Creates a step for unit testing. This only builds the test executable
     // but does not run it.
-    const unit_tests = b.addTest(.{
+    const main_tests = b.addTest(.{
         .root_source_file = .{ .path = "src/main.zig" },
         .target = target,
         .optimize = optimize,
     });
+    const lib_tests = b.addTest(.{
+        .root_source_file = .{ .path = "src/main-lib.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
 
-    const run_unit_tests = b.addRunArtifact(unit_tests);
+    const run_main_tests = b.addRunArtifact(main_tests);
+    const run_lib_tests = b.addRunArtifact(lib_tests);
 
-    // Similar to creating the run step earlier, this exposes a `test` step to
+    // This creates a build step. It will be visible in the `zig build --help` menu,
-    // the `zig build --help` menu, providing a way for the user to request
+    // and can be selected like this: `zig build test`
-    // running the unit tests.
+    // This will evaluate the `test` step rather than the default, which is "install".
     const test_step = b.step("test", "Run unit tests");
-    test_step.dependOn(&run_unit_tests.step);
+    test_step.dependOn(&run_main_tests.step);
+    test_step.dependOn(&run_lib_tests.step);
 }

src/main-lib.zig

@@ -0,0 +1,10 @@
+const std = @import("std");
+const testing = std.testing;
+
+export fn add(a: i32, b: i32) i32 {
+    return a + b;
+}
+
+test "basic add functionality" {
+    try testing.expect(add(3, 7) == 10);
+}