From 104d0e57cdd3f149b1c1f5704ff7379c5e92c3be Mon Sep 17 00:00:00 2001
From: Aaron L <aaron@bettercoder.net>
Date: Sat, 9 Jul 2016 09:53:21 -0700
Subject: [PATCH] Add nullability to foreign keys.

- Remove some debug output.
- Add some parallel
---
 bdb/column_test.go        |  2 ++
 bdb/interface.go          | 20 ++++++++++++++++++++
 bdb/interface_test.go     | 33 +++++++++++++++++++++++++++++++--
 bdb/keys.go               |  5 +++--
 bdb/relationships_test.go |  7 +------
 5 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/bdb/column_test.go b/bdb/column_test.go
index 567baad..bf8498c 100644
--- a/bdb/column_test.go
+++ b/bdb/column_test.go
@@ -53,6 +53,8 @@ func TestFilterColumnsByDefault(t *testing.T) {
 }
 
 func TestDefaultValues(t *testing.T) {
+	t.Parallel()
+
 	c := Column{}
 
 	c.Default = `\x12345678`
diff --git a/bdb/interface.go b/bdb/interface.go
index cc96b14..d3895ba 100644
--- a/bdb/interface.go
+++ b/bdb/interface.go
@@ -52,6 +52,7 @@ func Tables(db Interface, names ...string) ([]Table, error) {
 		}
 
 		setIsJoinTable(&t)
+		setForeignKeyNullability(&t)
 
 		tables = append(tables, t)
 	}
@@ -82,3 +83,22 @@ func setIsJoinTable(t *Table) {
 
 	t.IsJoinTable = true
 }
+
+func setForeignKeyNullability(t *Table) {
+	for i, fkey := range t.FKeys {
+
+		found := -1
+		for j, col := range t.Columns {
+			if col.Name == fkey.Column {
+				found = j
+				break
+			}
+		}
+
+		if found < 0 {
+			panic("could not find foreign key column in table")
+		}
+
+		t.FKeys[i].Nullable = t.Columns[found].IsNullable
+	}
+}
diff --git a/bdb/interface_test.go b/bdb/interface_test.go
index c71d6c8..1a5c4a3 100644
--- a/bdb/interface_test.go
+++ b/bdb/interface_test.go
@@ -14,7 +14,7 @@ func (t testInterface) TableNames() ([]string, error) {
 func (t testInterface) Columns(tableName string) ([]Column, error) {
 	return []Column{
 		Column{Name: "col1", Type: "character varying"},
-		Column{Name: "col2", Type: "character varying"},
+		Column{Name: "col2", Type: "character varying", IsNullable: true},
 	}, nil
 }
 
@@ -64,7 +64,7 @@ func TestTables(t *testing.T) {
 
 	expectCols := []Column{
 		Column{Name: "col1", Type: "string"},
-		Column{Name: "col2", Type: "string"},
+		Column{Name: "col2", Type: "string", IsNullable: true},
 	}
 
 	if !reflect.DeepEqual(tables[0].Columns, expectCols) {
@@ -88,6 +88,7 @@ func TestTables(t *testing.T) {
 			Column:        "col2",
 			ForeignTable:  "table3",
 			ForeignColumn: "col3",
+			Nullable:      true,
 		},
 	}
 
@@ -132,3 +133,31 @@ func TestSetIsJoinTable(t *testing.T) {
 		}
 	}
 }
+
+func TestSetForeignKeyNullability(t *testing.T) {
+	t.Parallel()
+
+	table := &Table{
+		Columns: []Column{
+			Column{Name: "col1", Type: "string"},
+			Column{Name: "col2", Type: "string", IsNullable: true},
+		},
+		FKeys: []ForeignKey{
+			{
+				Column: "col1",
+			},
+			{
+				Column: "col2",
+			},
+		},
+	}
+
+	setForeignKeyNullability(table)
+
+	if table.FKeys[0].Nullable {
+		t.Error("should not be nullable")
+	}
+	if !table.FKeys[1].Nullable {
+		t.Error("should be nullable")
+	}
+}
diff --git a/bdb/keys.go b/bdb/keys.go
index 8729f70..c8a3346 100644
--- a/bdb/keys.go
+++ b/bdb/keys.go
@@ -16,8 +16,9 @@ type PrimaryKey struct {
 
 // ForeignKey represents a foreign key constraint in a database
 type ForeignKey struct {
-	Name   string
-	Column string
+	Name     string
+	Column   string
+	Nullable bool
 
 	ForeignTable  string
 	ForeignColumn string
diff --git a/bdb/relationships_test.go b/bdb/relationships_test.go
index f510d87..1c0ca3b 100644
--- a/bdb/relationships_test.go
+++ b/bdb/relationships_test.go
@@ -1,10 +1,6 @@
 package bdb
 
-import (
-	"testing"
-
-	"github.com/davecgh/go-spew/spew"
-)
+import "testing"
 
 func TestToManyRelationships(t *testing.T) {
 	t.Parallel()
@@ -35,7 +31,6 @@ func TestToManyRelationships(t *testing.T) {
 	}
 
 	relationships := ToManyRelationships("users", tables)
-	spew.Dump(relationships)
 	if len(relationships) != 4 {
 		t.Error("wrong # of relationships:", len(relationships))
 	}