fix(codegen/golang): handle go_struct_tag for db_type overrides (#4055)

* fix(codegen/golang): handle `go_struct_tag` for `db_type` overrides

Resolves #3143

* update tests

* properly handle nullable and other db_type match parameters

* and update tests

Author: andrewmbenton

internal/codegen/golang/go_type.go

@@ -14,6 +14,12 @@ func addExtraGoStructTags(tags map[string]string, req *plugin.GenerateRequest, o
 		if oride.GoType.StructTags == nil {
 			continue
 		}
+		if override.MatchesColumn(col) {
+			for k, v := range oride.GoType.StructTags {
+				tags[k] = v
+			}
+			continue
+		}
 		if !override.Matches(col.Table, req.Catalog.DefaultSchema) {
 			// Different table.
 			continue
@@ -64,16 +70,13 @@ func goType(req *plugin.GenerateRequest, options *opts.Options, col *plugin.Colu
 }
 
 func goInnerType(req *plugin.GenerateRequest, options *opts.Options, col *plugin.Column) string {
-	columnType := sdk.DataType(col.Type)
-	notNull := col.NotNull || col.IsArray
-
 	// package overrides have a higher precedence
 	for _, override := range options.Overrides {
 		oride := override.ShimOverride
 		if oride.GoType.TypeName == "" {
 			continue
 		}
-		if oride.DbType != "" && oride.DbType == columnType && oride.Nullable != notNull && oride.Unsigned == col.Unsigned {
+		if override.MatchesColumn(col) {
 			return oride.GoType.TypeName
 		}
 	}

internal/codegen/golang/opts/override.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/sqlc-dev/sqlc/internal/codegen/sdk"
 	"github.com/sqlc-dev/sqlc/internal/pattern"
 	"github.com/sqlc-dev/sqlc/internal/plugin"
 )
@@ -76,6 +77,12 @@ func (o *Override) Matches(n *plugin.Identifier, defaultSchema string) bool {
 	return true
 }
 
+func (o *Override) MatchesColumn(col *plugin.Column) bool {
+	columnType := sdk.DataType(col.Type)
+	notNull := col.NotNull || col.IsArray
+	return o.DBType != "" && o.DBType == columnType && o.Nullable != notNull && o.Unsigned == col.Unsigned
+}
+
 func (o *Override) parse(req *plugin.GenerateRequest) (err error) {
 	// validate deprecated postgres_type field
 	if o.Deprecated_PostgresType != "" {

internal/endtoend/testdata/overrides_go_struct_tags/mysql/go/models.go

@@ -1,6 +1,7 @@
 CREATE TABLE foo (
     other     text NOT NULL,
-    tagged    text NOT NULL
+    tagged    text NOT NULL,
+    nulltext text
 );
 
 CREATE TABLE bar (

internal/endtoend/testdata/overrides_go_struct_tags/mysql/schema.sql

@@ -15,6 +15,16 @@
         {
           "go_struct_tag": "also:\"tagged\"",
           "column": "*.also_tagged"
+        },
+        {
+          "db_type": "text",
+          "go_struct_tag": "utype:\"notnull_text\""
+        },
+        {
+          "db_type": "text",
+          "go_type": "string",
+          "nullable": true,
+          "go_struct_tag": "utype:\"nullable_text\""
         }
       ]
     }

internal/endtoend/testdata/overrides_go_struct_tags/mysql/sqlc.json

@@ -2,7 +2,8 @@ CREATE TABLE foo (
     id       text,
     other_id text,
     about    text,
-    other    text
+    other    text,
+    notnulltext text not null
 );
 
 CREATE TABLE bar (

internal/endtoend/testdata/overrides_go_struct_tags/postgresql/pgx/v4/go/models.go

@@ -32,6 +32,16 @@
         {
           "column": "foo.other",
           "go_struct_tag": "type:\"this\""
+        },
+        {
+          "db_type": "text",
+          "go_struct_tag": "utype:\"notnull_text\""
+        },
+        {
+          "db_type": "text",
+          "go_type": "string",
+          "nullable": true,
+          "go_struct_tag": "utype:\"nullable_text\""
         }
       ]
     }

internal/endtoend/testdata/overrides_go_struct_tags/postgresql/pgx/v4/schema.sql

@@ -2,7 +2,8 @@ CREATE TABLE foo (
     id       text,
     other_id text,
     about    text,
-    other    text
+    other    text,
+    notnulltext text not null
 );
 
 CREATE TABLE bar (