Break up Gemtext link parsing code and improve tests.

2025-01-16 09:38:28 +02:00
parent 982fb75bd2
commit ea92b90c62
6 changed files with 231 additions and 93 deletions
--- a/gemini/gemini.go
+++ b/gemini/gemini.go
@@ -2,103 +2,12 @@ package gemini

 import (
 	"fmt"
-	"gemini-grc/common"
-	"net/url"
 	"regexp"
 	"strconv"

-	"gemini-grc/logging"
+	"gemini-grc/common"
 )

-func GetPageLinks(currentURL common.URL, gemtext string) common.LinkList {
-	// Grab link lines
-	linkLines := ExtractLinkLines(gemtext)
-	if len(linkLines) == 0 {
-		return nil
-	}
-	var linkURLs common.LinkList
-	// Normalize URLs in links, and store them in snapshot
-	for _, line := range linkLines {
-		linkURL, err := NormalizeLink(line, currentURL.String())
-		if err != nil {
-			logging.LogDebug("%s: %s", common.ErrGeminiLinkLineParse, err)
-			continue
-		}
-		linkURLs = append(linkURLs, *linkURL)
-	}
-	return linkURLs
-}
-
-// ExtractLinkLines takes a Gemtext document as a string and returns all lines that are link lines
-func ExtractLinkLines(gemtext string) []string {
-	// Define the regular expression pattern to match link lines
-	re := regexp.MustCompile(`(?m)^=>[ \t]+.*`)
-
-	// Find all matches using the regular expression
-	matches := re.FindAllString(gemtext, -1)
-
-	return matches
-}
-
-// NormalizeLink takes a single link line and the current URL,
-// return the URL converted to an absolute URL
-// and its description.
-func NormalizeLink(linkLine string, currentURL string) (*common.URL, error) {
-	// Parse the current URL
-	baseURL, err := url.Parse(currentURL)
-	if err != nil {
-		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
-	}
-
-	// Regular expression to extract the URL part from a link line
-	re := regexp.MustCompile(`^=>[ \t]+(\S+)([ \t]+.*)?`)
-
-	// Use regex to extract the URL and the rest of the line
-	matches := re.FindStringSubmatch(linkLine)
-	if len(matches) == 0 {
-		// If the line doesn't match the expected format, return it unchanged
-		return nil, fmt.Errorf("%w for link line %s", common.ErrGeminiLinkLineParse, linkLine)
-	}
-
-	originalURLStr := matches[1]
-	_, err = url.QueryUnescape(originalURLStr)
-	if err != nil {
-		return nil, fmt.Errorf("%w: %w", common.ErrURLDecode, err)
-	}
-
-	restOfLine := ""
-	if len(matches) > 2 {
-		restOfLine = matches[2]
-	}
-
-	// Parse the URL from the link line
-	parsedURL, err := url.Parse(originalURLStr)
-	if err != nil {
-		// If URL parsing fails, return an error
-		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
-	}
-
-	// Resolve relative URLs against the base URL
-	if !parsedURL.IsAbs() {
-		parsedURL = baseURL.ResolveReference(parsedURL)
-	}
-
-	// Remove usual first space from URL description:
-	// => URL description
-	//       ^^^^^^^^^^^^
-	if len(restOfLine) > 0 && restOfLine[0] == ' ' {
-		restOfLine = restOfLine[1:]
-	}
-
-	finalURL, err := common.ParseURL(parsedURL.String(), restOfLine)
-	if err != nil {
-		// If URL parsing fails, return an error
-		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
-	}
-
-	return finalURL, nil
-}
-
 // ParseFirstTwoDigits takes a string and returns the first one or two digits as an int.
 // If no valid digits are found, it returns an error.
 func ParseFirstTwoDigits(input string) (int, error) {
--- a/gemini/geminiLinks.go
+++ b/gemini/geminiLinks.go
@@ -0,0 +1,88 @@
+package gemini
+
+import (
+	"fmt"
+	"net/url"
+	"regexp"
+
+	"gemini-grc/common"
+	"gemini-grc/logging"
+	"gemini-grc/util"
+)
+
+func GetPageLinks(currentURL common.URL, gemtext string) common.LinkList {
+	linkLines := util.GetLinesMatchingRegex(gemtext, `(?m)^=>[ \t]+.*`)
+	if len(linkLines) == 0 {
+		return nil
+	}
+	var linkURLs common.LinkList
+	// Normalize URLs in links
+	for _, line := range linkLines {
+		linkUrl, err := ParseGeminiLinkLine(line, currentURL.String())
+		if err != nil {
+			logging.LogDebug("%s: %s", common.ErrGeminiLinkLineParse, err)
+			continue
+		}
+		linkURLs = append(linkURLs, *linkUrl)
+	}
+	return linkURLs
+}
+
+// ParseGeminiLinkLine takes a single link line and the current URL,
+// return the URL converted to an absolute URL
+// and its description.
+func ParseGeminiLinkLine(linkLine string, currentURL string) (*common.URL, error) {
+	// Check: currentURL is parseable
+	baseURL, err := url.Parse(currentURL)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
+	}
+
+	// Extract the actual URL and the description
+	re := regexp.MustCompile(`^=>[ \t]+(\S+)([ \t]+.*)?`)
+	matches := re.FindStringSubmatch(linkLine)
+	if len(matches) == 0 {
+		// If the line doesn't match the expected format, return it unchanged
+		return nil, fmt.Errorf("%w could not parse gemini link %s", common.ErrGeminiLinkLineParse, linkLine)
+	}
+
+	originalURLStr := matches[1]
+
+	// Check: Unescape the URL if escaped
+	_, err = url.QueryUnescape(originalURLStr)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %w", common.ErrURLDecode, err)
+	}
+
+	description := ""
+	if len(matches) > 2 {
+		description = matches[2]
+	}
+
+	// Parse the URL from the link line
+	parsedURL, err := url.Parse(originalURLStr)
+	if err != nil {
+		// If URL parsing fails, return an error
+		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
+	}
+
+	// If link URL is relative, resolve full URL
+	if !parsedURL.IsAbs() {
+		parsedURL = baseURL.ResolveReference(parsedURL)
+	}
+
+	// Remove usual first space from URL description:
+	// => URL description
+	//       ^^^^^^^^^^^^
+	if len(description) > 0 && description[0] == ' ' {
+		description = description[1:]
+	}
+	
+	finalURL, err := common.ParseURL(parsedURL.String(), description)
+	if err != nil {
+		// If URL parsing fails, return an error
+		return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
+	}
+
+	return finalURL, nil
+}
--- a/gemini/geminiLinks_test.go
+++ b/gemini/geminiLinks_test.go
@@ -0,0 +1,125 @@
+package gemini
+
+import (
+	"errors"
+	"reflect"
+	"testing"
+
+	"gemini-grc/common"
+)
+
+type TestData struct {
+	currentURL string
+	link       string
+	value      *common.URL
+	error      error
+}
+
+var data = []TestData{
+	{
+		currentURL: "https://gemini.com/",
+		link:       "https://gemini.com/",
+		value:      nil,
+		error:      common.ErrGeminiLinkLineParse,
+	},
+	{
+		currentURL: "gemini://gemi.dev/cgi-bin/xkcd/",
+		link:       "=> archive/ Complete Archive",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "gemi.dev",
+			Port:     1965,
+			Path:     "/cgi-bin/xkcd/archive/",
+			Descr:    "Complete Archive",
+			Full:     "gemini://gemi.dev:1965/cgi-bin/xkcd/archive/",
+		},
+		error: nil,
+	},
+	{
+		currentURL: "gemini://gemi.dev/cgi-bin/xkcd/",
+		link:       "=> /cgi-bin/xkcd.cgi?a=5&b=6 Example",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "gemi.dev",
+			Port:     1965,
+			Path:     "/cgi-bin/xkcd.cgi",
+			Descr:    "Example",
+			Full:     "gemini://gemi.dev:1965/cgi-bin/xkcd.cgi?a=5&b=6",
+		},
+		error: nil,
+	},
+	{
+		currentURL: "gemini://gemi.dev/cgi-bin/xkcd/",
+		link:       "=> /cgi-bin/xkcd.cgi?1494 XKCD 1494: Insurance",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "gemi.dev",
+			Port:     1965,
+			Path:     "/cgi-bin/xkcd.cgi",
+			Descr:    "XKCD 1494: Insurance",
+			Full:     "gemini://gemi.dev:1965/cgi-bin/xkcd.cgi?1494",
+		},
+		error: nil,
+	},
+	{
+		currentURL: "gemini://gemi.dev/cgi-bin/xkcd/",
+		link:       "=> /cgi-bin/xkcd.cgi?1494#f XKCD 1494: Insurance",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "gemi.dev",
+			Port:     1965,
+			Path:     "/cgi-bin/xkcd.cgi",
+			Descr:    "XKCD 1494: Insurance",
+			Full:     "gemini://gemi.dev:1965/cgi-bin/xkcd.cgi?1494#f",
+		},
+		error: nil,
+	},
+	{
+		currentURL: "gemini://gemi.dev/cgi-bin/xkcd/",
+		link:       "=> /cgi-bin/xkcd.cgi?c=5#d XKCD 1494: Insurance",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "gemi.dev",
+			Port:     1965,
+			Path:     "/cgi-bin/xkcd.cgi",
+			Descr:    "XKCD 1494: Insurance",
+			Full:     "gemini://gemi.dev:1965/cgi-bin/xkcd.cgi?c=5#d",
+		},
+		error: nil,
+	},
+	{
+		currentURL: "gemini://a.b/c#d",
+		link:       "=> /d/e#f",
+		value: &common.URL{
+			Protocol: "gemini",
+			Hostname: "a.b",
+			Port:     1965,
+			Path:     "/d/e",
+			Descr:    "",
+			Full:     "gemini://a.b:1965/d/e#f",
+		},
+		error: nil,
+	},
+}
+
+func Test(t *testing.T) {
+	t.Parallel()
+	for i, expected := range data {
+		result, err := ParseGeminiLinkLine(expected.link, expected.currentURL)
+		if err != nil { //nolint:nestif
+			if expected.value != nil {
+				t.Errorf("data[%d]: Expected value %v, got %v", i, nil, expected.value)
+			}
+			if !errors.Is(err, common.ErrGeminiLinkLineParse) {
+				t.Errorf("data[%d]: expected error %v, got %v", i, expected.error, err)
+			}
+		} else {
+			if expected.error != nil {
+				t.Errorf("data[%d]: Expected error %v, got %v", i, nil, expected.error)
+			}
+			if !(reflect.DeepEqual(result, expected.value)) {
+				t.Errorf("data[%d]: expected %#v, got %#v", i, expected.value, result)
+			}
+		}
+	}
+}
--- a/gemini/gemini_test.go
+++ b/gemini/gemini_test.go
@@ -1,8 +1,9 @@
 package gemini

 import (
-	"gemini-grc/common"
 	"testing"
+
+	"gemini-grc/common"
 )

 func TestExtractRedirectTargetFullURL(t *testing.T) {