feat: unit tests for parsing

example/my-manifest.yaml

@@ -1,6 +1,8 @@
 apiVersion: example.com/v1alpha1
 kind: MyManifest
+
 metadata:
   name: my-manifest
+
 spec:
   message: hello, world

manifesto_test.go

@@ -0,0 +1,79 @@
+package manifesto
+
+import (
+	"io"
+	"strings"
+	"testing"
+)
+
+type MySpec struct {
+	Message string `yaml:"message" json:"message"`
+}
+
+func TestParseFile(t *testing.T) {
+	manifest := ParseFile("example/my-manifest.yaml", &MySpec{}, &MySpec{})
+	spec := manifest.Spec.(*MySpec)
+
+	want := manifest.Metadata.Name == "my-manifest" && spec.Message == "hello, world"
+
+	if !want {
+		t.Fatalf("Unable to parse manifest from file")
+	}
+}
+
+func TestParseReader(t *testing.T) {
+	r := io.NopCloser(strings.NewReader(`apiVersion: example.com/v1alpha1
+kind: MyManifest
+metadata:
+  name: my-manifest
+spec:
+  message: hello, world
+    `))
+	manifest := ParseReader(r, &MySpec{}, &MySpec{})
+
+	spec := manifest.Spec.(*MySpec)
+
+	want := manifest.Metadata.Name == "my-manifest" && spec.Message == "hello, world"
+
+	if !want {
+		t.Fatalf("Unable to parse manifest from reader")
+	}
+}
+
+func TestParseString(t *testing.T) {
+	s := `apiVersion: example.com/v1alpha1
+kind: MyManifest
+metadata:
+  name: my-manifest
+spec:
+  message: hello, world
+    `
+	manifest := ParseString(s, &MySpec{}, &MySpec{})
+
+	spec := manifest.Spec.(*MySpec)
+
+	want := manifest.Metadata.Name == "my-manifest" && spec.Message == "hello, world"
+
+	if !want {
+		t.Fatalf("Unable to parse manifest from string")
+	}
+}
+
+func TestParseBytes(t *testing.T) {
+	b := []byte(`apiVersion: example.com/v1alpha1
+kind: MyManifest
+metadata:
+  name: my-manifest
+spec:
+  message: hello, world
+    `)
+	manifest := ParseBytes(b, &MySpec{}, &MySpec{})
+
+	spec := manifest.Spec.(*MySpec)
+
+	want := manifest.Metadata.Name == "my-manifest" && spec.Message == "hello, world"
+
+	if !want {
+		t.Fatalf("Unable to parse manifest from bytes")
+	}
+}