chore: add existing code to project

I also ran go mod tidy since the new files refer to packages I've
recently installed (locally.)

1 files changed, 44 insertions, 0 deletions

diff --git a/fetch.go b/fetch.go
new file mode 100644
index 0000000..f81f327
--- /dev/null
+++ b/fetch.go
@@ -0,0 +1,44 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"golang.org/x/net/html"
+)
+
+// fetch makes a GET request to refURL, returning the HTML contents of
+// that webpage. An error is also returned.
+//
+// A [url.URL] type is used for refURL to simplify recursive or else
+// repeated use of this function when crawling webpages to, say, build
+// a sitemap.
+func fetch(refURL url.URL) (*html.Node, error) {
+	rawURL := refURL.String()
+
+	// For now we leave the client unconfigured.
+	client := http.Client{}
+
+	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("can't create request: %w", err)
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("client failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("status for %s for %s: %s", http.MethodGet, rawURL, resp.Status)
+	}
+
+	htmlDoc, err := html.Parse(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("can't parse response body: %w", err)
+	}
+
+	return htmlDoc, nil
+}