Add support for redirects24-add-redirects

Fix https://gitlab.com/gitlab-org/gitlab-pages/-/issues/24

1 files changed, 296 insertions, 0 deletions

diff --git a/internal/redirects/redirects_test.go b/internal/redirects/redirects_test.go
new file mode 100644
index 00000000..f538fc4b
--- /dev/null
+++ b/internal/redirects/redirects_test.go
@@ -0,0 +1,296 @@
+package redirects
+
+import (
+	"context"
+	"io/ioutil"
+	"net/url"
+	"path"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	netlifyRedirects "github.com/tj/go-redirects"
+
+	"gitlab.com/gitlab-org/gitlab-pages/internal/testhelpers"
+)
+
+func TestRedirectsValidateUrl(t *testing.T) {
+	tests := []struct {
+		name        string
+		url         string
+		expectedErr string
+	}{
+		{
+			name:        "Valid url",
+			url:         "/goto.html",
+			expectedErr: "",
+		},
+		{
+			name:        "No domain-level redirects",
+			url:         "https://GitLab.com",
+			expectedErr: errNoDomainLevelRedirects.Error(),
+		},
+		{
+			name:        "No Schema-less URL domain-level redirects",
+			url:         "//GitLab.com/pages.html",
+			expectedErr: errNoDomainLevelRedirects.Error(),
+		},
+		{
+			name:        "No bare domain-level redirects",
+			url:         "GitLab.com",
+			expectedErr: errNoStartingForwardSlashInURLPath.Error(),
+		},
+		{
+			name:        "No parent traversing relative URL",
+			url:         "../target.html",
+			expectedErr: errNoStartingForwardSlashInURLPath.Error(),
+		},
+		{
+			name:        "No splats",
+			url:         "/blog/*",
+			expectedErr: errNoSplats.Error(),
+		},
+		{
+			name:        "No Placeholders",
+			url:         "/news/:year/:month/:date/:slug",
+			expectedErr: errNoPlaceholders.Error(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateURL(tt.url)
+			if tt.expectedErr != "" {
+				require.EqualError(t, err, tt.expectedErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestRedirectsValidateRule(t *testing.T) {
+	tests := []struct {
+		name        string
+		rule        string
+		expectedErr string
+	}{
+		{
+			name:        "valid rule",
+			rule:        "/goto.html /target.html 301",
+			expectedErr: "",
+		},
+		{
+			name:        "invalid From URL",
+			rule:        "invalid.com /teapot.html 302",
+			expectedErr: errNoStartingForwardSlashInURLPath.Error(),
+		},
+		{
+			name:        "invalid To URL",
+			rule:        "/goto.html invalid.com",
+			expectedErr: errNoStartingForwardSlashInURLPath.Error(),
+		},
+		{
+			name: "No parameters",
+			rule: "/	/something	302	foo=bar",
+			expectedErr: errNoParams.Error(),
+		},
+		{
+			name:        "Invalid status",
+			rule:        "/goto.html /target.html 418",
+			expectedErr: errUnsupportedStatus.Error(),
+		},
+		{
+			name:        "Force not supported",
+			rule:        "/goto.html /target.html 302!",
+			expectedErr: errNoForce.Error(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			rules, err := netlifyRedirects.ParseString(tt.rule)
+			require.NoError(t, err)
+
+			err = validateRule(rules[0])
+			if tt.expectedErr != "" {
+				require.EqualError(t, err, tt.expectedErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestRedirectsRewrite(t *testing.T) {
+	tests := []struct {
+		name           string
+		url            string
+		rule           string
+		expectedURL    string
+		expectedStatus int
+		expectedErr    string
+	}{
+		{
+			name:           "No rules given",
+			url:            "/no-redirect/",
+			rule:           "",
+			expectedURL:    "",
+			expectedStatus: 0,
+			expectedErr:    ErrNoRedirect.Error(),
+		},
+		{
+			name:           "No matching rules",
+			url:            "/no-redirect/",
+			rule:           "/cake-portal.html  /still-alive.html 301",
+			expectedURL:    "",
+			expectedStatus: 0,
+			expectedErr:    ErrNoRedirect.Error(),
+		},
+		{
+			name:           "Matching rule redirects",
+			url:            "/cake-portal.html",
+			rule:           "/cake-portal.html  /still-alive.html 301",
+			expectedURL:    "/still-alive.html",
+			expectedStatus: 301,
+			expectedErr:    "",
+		},
+		{
+			name:           "Does not redirect to invalid rule",
+			url:            "/goto.html",
+			rule:           "/goto.html GitLab.com 301",
+			expectedURL:    "",
+			expectedStatus: 0,
+			expectedErr:    ErrNoRedirect.Error(),
+		},
+		{
+			name:           "Matches trailing slash rule to no trailing slash URL",
+			url:            "/cake-portal",
+			rule:           "/cake-portal/  /still-alive/ 301",
+			expectedURL:    "/still-alive/",
+			expectedStatus: 301,
+			expectedErr:    "",
+		},
+		{
+			name:           "Matches trailing slash rule to trailing slash URL",
+			url:            "/cake-portal/",
+			rule:           "/cake-portal/  /still-alive/ 301",
+			expectedURL:    "/still-alive/",
+			expectedStatus: 301,
+			expectedErr:    "",
+		},
+		{
+			name:           "Matches no trailing slash rule to no trailing slash URL",
+			url:            "/cake-portal",
+			rule:           "/cake-portal  /still-alive 301",
+			expectedURL:    "/still-alive",
+			expectedStatus: 301,
+			expectedErr:    "",
+		},
+		{
+			name:           "Matches no trailing slash rule to trailing slash URL",
+			url:            "/cake-portal/",
+			rule:           "/cake-portal  /still-alive 301",
+			expectedURL:    "/still-alive",
+			expectedStatus: 301,
+			expectedErr:    "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := Redirects{}
+
+			if tt.rule != "" {
+				rules, err := netlifyRedirects.ParseString(tt.rule)
+				require.NoError(t, err)
+				r.rules = rules
+			}
+
+			url, err := url.Parse(tt.url)
+			require.NoError(t, err)
+
+			toURL, status, err := r.Rewrite(url)
+
+			if tt.expectedURL != "" {
+				require.Equal(t, tt.expectedURL, toURL.String())
+			} else {
+				require.Nil(t, toURL)
+			}
+
+			require.Equal(t, tt.expectedStatus, status)
+
+			if tt.expectedErr != "" {
+				require.EqualError(t, err, tt.expectedErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestRedirectsParseRedirects(t *testing.T) {
+	ctx := context.Background()
+
+	root, tmpDir, cleanup := testhelpers.TmpDir(t, "ParseRedirects_tests")
+	defer cleanup()
+
+	tests := []struct {
+		name          string
+		redirectsFile string
+		expectedRules int
+		expectedErr   string
+	}{
+		{
+			name:          "No `_redirects` file present",
+			redirectsFile: "",
+			expectedRules: 0,
+			expectedErr:   errConfigNotFound.Error(),
+		},
+		{
+			name:          "Everything working as expected",
+			redirectsFile: `/goto.html /target.html 301`,
+			expectedRules: 1,
+			expectedErr:   "",
+		},
+		{
+			name:          "Invalid _redirects syntax gives no rules",
+			redirectsFile: `foobar::baz`,
+			expectedRules: 0,
+			expectedErr:   "",
+		},
+		{
+			name:          "Config file too big",
+			redirectsFile: strings.Repeat("a", 2*maxConfigSize),
+			expectedRules: 0,
+			expectedErr:   errFileTooLarge.Error(),
+		},
+		// In future versions of `github.com/tj/go-redirects`,
+		// this may not throw a parsing error and this test could be removed
+		{
+			name:          "Parsing error is caught",
+			redirectsFile: "/store id=:id  /blog/:id  301",
+			expectedRules: 0,
+			expectedErr:   errFailedToParseConfig.Error(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.redirectsFile != "" {
+				err := ioutil.WriteFile(path.Join(tmpDir, ConfigFile), []byte(tt.redirectsFile), 0600)
+				require.NoError(t, err)
+			}
+
+			redirects := ParseRedirects(ctx, root)
+
+			if tt.expectedErr != "" {
+				require.EqualError(t, redirects.error, tt.expectedErr)
+			} else {
+				require.NoError(t, redirects.error)
+			}
+
+			require.Len(t, redirects.rules, tt.expectedRules)
+		})
+	}
+}