feat: go greenlight api wip

projects/greenlight/internal/data/runtime.go

@@ -0,0 +1,25 @@
+package data
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// Declare a custom Runtime type, which has the underlying type int32 (the same as our
+// Movie struct field).
+type Runtime int32
+
+// Implement a MarshalJSON() method on the Runtime type so that it satisfies the
+// json.Marshaler interface. This should return the JSON-encoded value for the movie
+// runtime (in our case, it will return a string in the format "<runtime> mins").
+func (r Runtime) MarshalJSON() ([]byte, error) {
+	// Generate a string containing the movie runtime in the required format.
+	jsonValue := fmt.Sprintf("%d mins", r)
+
+	// Use the strconv.Quote() function on the string to wrap it in double quotes. It
+	// needs to be surrounded by double quotes in order to be a valid *JSON string*.
+	quotedJSONValue := strconv.Quote(jsonValue)
+
+	// Convert the quoted string value to a byte slice and return it.
+	return []byte(quotedJSONValue), nil
+}