Refactor tests into build.zig

I like seeing the summary of each module, instead of all tests
grouped together.

build.zig

@@ -12,14 +12,29 @@ pub fn build(b: *std.Build) void {
 
  _ = buildModule(b, "zignal", target, optimize);
 
- const unit_tests = b.addTest(.{
- .root_source_file = .{ .path = "src/tests.zig" },
- .target = target,
- .optimize = optimize,
+ const test_step = b.step("test", "Run library tests");
+ for ([_][]const u8{
+ "color",
+ "matrix",
+ "svd",
+ }) |module| {
+ const module_test = b.addTest(.{
+ .name = module,
+ .root_source_file = .{ .path = b.fmt("src/{s}.zig", .{module}) },
+ .target = target,
+ .optimize = optimize,
+ });
+ const module_test_run = b.addRunArtifact(module_test);
+ test_step.dependOn(&module_test_run.step);
+ }
+
+ const fmt_step = b.step("fmt", "Run zig fmt");
+ const fmt = b.addFmt(.{
+ .paths = &.{ "src", "build.zig" },
+ .check = true,
  });
- const run_unit_tests = b.addRunArtifact(unit_tests);
- const test_step = b.step("test", "Run unit tests");
- test_step.dependOn(&run_unit_tests.step);
+ fmt_step.dependOn(&fmt.step);
+ b.default_step.dependOn(fmt_step);
 }
 
 fn buildModule(

src/zignal.zig

@@ -11,3 +11,5 @@ pub const Point2d = @import("point.zig").Point2d;
 pub const Point3d = @import("point.zig").Point3d;
 
 pub const Matrix = @import("matrix.zig").Matrix;
+
+pub const svd = @import("svd.zig").svd;