From eaa4cddb2beaa2e2a62cafbf234b8b6233d89f21 Mon Sep 17 00:00:00 2001
From: Neil Macneale IV <neil@dolthub.com>
Date: Tue, 16 May 2023 14:15:30 -0700
Subject: [PATCH] Allow for unresolved targetEnvironment.

Not all commands, or even all SQL statements need databases.
---
 go/cmd/dolt/dolt.go                           | 37 +++++++++----------
 go/libraries/doltcore/env/multi_repo_env.go   | 20 ++++++----
 .../bats/sql-create-database.bats             |  1 +
 integration-tests/bats/sql.bats               |  2 +-
 4 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/go/cmd/dolt/dolt.go b/go/cmd/dolt/dolt.go
index aab3290041..9383900a2c 100644
--- a/go/cmd/dolt/dolt.go
+++ b/go/cmd/dolt/dolt.go
@@ -518,31 +518,28 @@ func buildLateBinder(ctx context.Context, dEnv *env.DoltEnv, mrEnv *env.MultiRep
 		useDb = mrEnv.GetFirstDatabase()
 	}
 
-	if targetEnv == nil {
+	if targetEnv == nil && useDb != "" {
 		targetEnv = mrEnv.GetEnv(useDb)
-		if targetEnv == nil {
-			return nil, fmt.Errorf("database %s doesn't exist.", useDb)
+	}
+
+	// nil targetEnv will happen if the user ran a command in an empty directory - which we support in some cases.
+	if targetEnv != nil {
+		isLocked, lock, err := targetEnv.GetLock()
+		if err != nil {
+			return nil, err
+		}
+		if isLocked {
+			if verbose {
+				cli.Println("verbose: starting remote mode")
+			}
+			return sqlserver.BuildConnectionStringQueryist(ctx, dEnv, apr, lock.Port, useDb)
 		}
 	}
 
-	isLocked, lock, err := targetEnv.GetLock()
-	if err != nil {
-		return nil, err
-	}
-	if isLocked {
-		if verbose {
-			cli.Println("verbose: starting remote mode")
-		}
-
-		mrEnv.GetFirstDatabase()
-
-		return sqlserver.BuildConnectionStringQueryist(ctx, dEnv, apr, lock.Port, useDb)
-	} else {
-		if verbose {
-			cli.Println("verbose: starting local mode")
-		}
-		return commands.BuildSqlEngineQueryist(ctx, dEnv, mrEnv, apr)
+	if verbose {
+		cli.Println("verbose: starting local mode")
 	}
+	return commands.BuildSqlEngineQueryist(ctx, dEnv, mrEnv, apr)
 }
 
 // splitArgsOnSubCommand splits the args into two slices, the first containing all args before the first subcommand,
diff --git a/go/libraries/doltcore/env/multi_repo_env.go b/go/libraries/doltcore/env/multi_repo_env.go
index 556cbc6bdc..0a9c41221f 100644
--- a/go/libraries/doltcore/env/multi_repo_env.go
+++ b/go/libraries/doltcore/env/multi_repo_env.go
@@ -69,35 +69,39 @@ func MultiEnvForSingleEnv(ctx context.Context, env *DoltEnv) (*MultiRepoEnv, err
 func MultiEnvForDirectory(
 	ctx context.Context,
 	config config.ReadWriteConfig,
-	fs filesys.Filesys,
+	fs filesys.Filesys, // fs which is the root of the multi-env. This is essentially the --data-dir flag or cwd.
 	version string,
 	ignoreLockFile bool,
 	dEnv *DoltEnv,
 ) (*MultiRepoEnv, error) {
 	// Load current fs and put into mr env
-	var dbName string
-	if _, ok := fs.(*filesys.InMemFS); ok {
-		dbName = "dolt"
-	} else {
+	var dbName string = "dolt"
+	var newDEnv *DoltEnv = dEnv
+
+	// InMemFS is used only for testing.
+	// All other FS Types should get a newly created Envronment which will serve as the primary env in the MultiRepoEnv
+	if _, ok := fs.(*filesys.InMemFS); !ok {
 		path, err := fs.Abs("")
 		if err != nil {
 			return nil, err
 		}
 		envName := getRepoRootDir(path, string(os.PathSeparator))
 		dbName = dirToDBName(envName)
+
+		newDEnv = Load(ctx, GetCurrentUserHomeDir, fs, doltdb.LocalDirDoltDB, version)
 	}
 
 	mrEnv := &MultiRepoEnv{
 		envs:           make([]NamedEnv, 0),
 		fs:             fs,
 		cfg:            config,
-		dialProvider:   NewGRPCDialProviderFromDoltEnv(dEnv),
+		dialProvider:   NewGRPCDialProviderFromDoltEnv(newDEnv),
 		ignoreLockFile: ignoreLockFile,
 	}
 
 	envSet := map[string]*DoltEnv{}
-	if dEnv.Valid() {
-		envSet[dbName] = dEnv
+	if newDEnv.Valid() {
+		envSet[dbName] = newDEnv
 	}
 
 	// If there are other directories in the directory, try to load them as additional databases
diff --git a/integration-tests/bats/sql-create-database.bats b/integration-tests/bats/sql-create-database.bats
index 88434bd5e1..444e971d23 100644
--- a/integration-tests/bats/sql-create-database.bats
+++ b/integration-tests/bats/sql-create-database.bats
@@ -1,3 +1,4 @@
+#!/usr/bin/env bats
 load $BATS_TEST_DIRNAME/helper/common.bash
 
 setup() {
diff --git a/integration-tests/bats/sql.bats b/integration-tests/bats/sql.bats
index 598965a2b9..6f5c2763fb 100755
--- a/integration-tests/bats/sql.bats
+++ b/integration-tests/bats/sql.bats
@@ -2828,5 +2828,5 @@ SQL
     # Use of the use-db flag when we have a different DB specified by data-dir should error.
     run dolt --data-dir="$ROOT_DIR/dbb" --use-db=dba sql -q "show tables"
     [ "$status" -eq 1 ]
-    [[ "$output" =~ "database not found" ]] || false
+    [[ "$output" =~ "provided --use-db dba does not exist or is not a directory" ]] || false
 }