Add pgroll latest url command

cli-definition.json

@@ -138,6 +138,24 @@
           ],
           "subcommands": [],
           "args": []
+        },
+        {
+          "name": "url",
+          "short": "Print a database connection URL for the latest schema version",
+          "use": "url",
+          "example": "pgroll latest url <connection-string> --local ./migrations",
+          "flags": [
+            {
+              "name": "local",
+              "shorthand": "l",
+              "description": "retrieve the latest schema version from a local migration directory",
+              "default": ""
+            }
+          ],
+          "subcommands": [],
+          "args": [
+            "connection-string"
+          ]
         }
       ],
       "args": []

cmd/latest.go

@@ -15,6 +15,7 @@ func latestCmd() *cobra.Command {
 
 	latestCmd.AddCommand(latestSchemaCmd())
 	latestCmd.AddCommand(latestMigrationCmd())
+	latestCmd.AddCommand(latestURLCmd())
 
 	return latestCmd
 }

cmd/latest_url.go

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+	"github.com/xataio/pgroll/cmd/flags"
+	"github.com/xataio/pgroll/internal/connstr"
+)
+
+func latestURLCmd() *cobra.Command {
+	var migrationsDir string
+
+	urlCmd := &cobra.Command{
+		Use:       "url",
+		Short:     "Print a database connection URL for the latest schema version",
+		Long:      "Print a database connection URL for the latest schema version, either from the target database or a local directory",
+		Example:   "pgroll latest url <connection-string> --local ./migrations",
+		Args:      cobra.MaximumNArgs(1),
+		ValidArgs: []string{"connection-string"},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx := cmd.Context()
+
+			// Default to the Postgres URL from flags, or use the first argument if provided
+			pgURL := flags.PostgresURL()
+			if len(args) > 0 {
+				pgURL = args[0]
+			}
+
+			// Get the latest version schema name, either from the remote database or a local directory
+			latestVersion, err := latestVersion(ctx, migrationsDir)
+			if err != nil {
+				return fmt.Errorf("failed to get latest version: %w", err)
+			}
+
+			// Append the search_path option to the connection string
+			str, err := connstr.AppendSearchPathOption(pgURL, latestVersion)
+			if err != nil {
+				return fmt.Errorf("failed to add search_path option: %w", err)
+			}
+
+			fmt.Println(str)
+
+			return nil
+		},
+	}
+
+	urlCmd.Flags().StringVarP(&migrationsDir, "local", "l", "", "retrieve the latest schema version from a local migration directory")
+
+	return urlCmd
+}

internal/connstr/connstr.go

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package connstr
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+// AppendSearchPathOption take a Postgres connection string in URL format and
+// produces the same connection string with the search_path option set to the
+// provided schema.
+func AppendSearchPathOption(connStr, schema string) (string, error) {
+	u, err := url.Parse(connStr)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse connection string: %w", err)
+	}
+
+	if schema == "" {
+		return connStr, nil
+	}
+
+	q := u.Query()
+	q.Set("options", fmt.Sprintf("-c search_path=%s", schema))
+	encodedQuery := q.Encode()
+
+	// Replace '+' with '%20' to ensure proper encoding of spaces within the
+	// `options` query parameter.
+	encodedQuery = strings.ReplaceAll(encodedQuery, "+", "%20")
+
+	u.RawQuery = encodedQuery
+
+	return u.String(), nil
+}

internal/connstr/connstr_test.go

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package connstr_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/xataio/pgroll/internal/connstr"
+)
+
+func TestAppendSearchPathOption(t *testing.T) {
+	tests := []struct {
+		Name     string
+		ConnStr  string
+		Schema   string
+		Expected string
+	}{
+		{
+			Name:     "empty schema doesn't change connection string",
+			ConnStr:  "postgres://postgres:postgres@localhost:5432?sslmode=disable",
+			Schema:   "",
+			Expected: "postgres://postgres:postgres@localhost:5432?sslmode=disable",
+		},
+		{
+			Name:     "can set options as the only query parameter",
+			ConnStr:  "postgres://postgres:postgres@localhost:5432",
+			Schema:   "apples",
+			Expected: "postgres://postgres:postgres@localhost:5432?options=-c%20search_path%3Dapples",
+		},
+		{
+			Name:     "can set options as an additional query parameter",
+			ConnStr:  "postgres://postgres:postgres@localhost:5432?sslmode=disable",
+			Schema:   "bananas",
+			Expected: "postgres://postgres:postgres@localhost:5432?options=-c%20search_path%3Dbananas&sslmode=disable",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			result, err := connstr.AppendSearchPathOption(tt.ConnStr, tt.Schema)
+			assert.NoError(t, err)
+
+			assert.Equal(t, tt.Expected, result)
+		})
+	}
+}