Fix strmangle's AutoIncPrimaryKey function.

- It's test was also a dead unicorn of unhappiness.

strmangle/strmangle.go

@@ -302,15 +302,18 @@ func AutoIncPrimaryKey(cols []dbdrivers.Column, pkey *dbdrivers.PrimaryKey) stri
 		return ""
 	}
 
+	for _, pkeyColumn := range pkey.Columns {
 		for _, c := range cols {
-		if rgxAutoIncColumn.MatchString(c.Default) &&
-			c.IsNullable == false &&
-			(strings.HasPrefix(c.Type, "int") || strings.HasPrefix(c.Type, "uint")) {
-			for _, p := range pkey.Columns {
-				if c.Name == p {
-					return p
+			if c.Name != pkeyColumn {
+				continue
 			}
+
+			if !rgxAutoIncColumn.MatchString(c.Default) || c.IsNullable ||
+				!(strings.HasPrefix(c.Type, "int") || strings.HasPrefix(c.Type, "uint")) {
+				continue
 			}
+
+			return pkeyColumn
 		}
 	}
 

strmangle/strmangle_test.go

@@ -90,57 +90,93 @@ func TestCamelCaseCommaList(t *testing.T) {
 func TestAutoIncPrimaryKey(t *testing.T) {
 	t.Parallel()
 
-	var pkey *dbdrivers.PrimaryKey
-	var cols []dbdrivers.Column
-
-	r := AutoIncPrimaryKey(cols, pkey)
-	if r != "" {
-		t.Errorf("Expected empty string, got %s", r)
-	}
-
-	pkey = &dbdrivers.PrimaryKey{
-		Columns: []string{
-			"col1", "auto",
+	tests := map[string]struct {
+		Expect  string
+		Pkey    *dbdrivers.PrimaryKey
+		Columns []dbdrivers.Column
+	}{
+		"easycase": {
+			Expect: "one",
+			Pkey: &dbdrivers.PrimaryKey{
+				Name:    "pkey",
+				Columns: []string{"one"},
 			},
-		Name: "",
-	}
-
-	cols = []dbdrivers.Column{
-		{
-			Name:       "thing",
-			IsNullable: true,
-			Type:       "int64",
-			Default:    "nextval('abc'::regclass)",
-		},
-		{
-			Name:       "stuff",
+			Columns: []dbdrivers.Column{
+				dbdrivers.Column{
+					Name:       "one",
+					Type:       "int32",
 					IsNullable: false,
+					Default:    `nextval('abc'::regclass)`,
+				},
+			},
+		},
+		"missingcase": {
+			Expect: "",
+			Pkey: &dbdrivers.PrimaryKey{
+				Name:    "pkey",
+				Columns: []string{"two"},
+			},
+			Columns: []dbdrivers.Column{
+				dbdrivers.Column{
+					Name:       "one",
+					Type:       "int32",
+					IsNullable: false,
+					Default:    `nextval('abc'::regclass)`,
+				},
+			},
+		},
+		"wrongtype": {
+			Expect: "",
+			Pkey: &dbdrivers.PrimaryKey{
+				Name:    "pkey",
+				Columns: []string{"one"},
+			},
+			Columns: []dbdrivers.Column{
+				dbdrivers.Column{
+					Name:       "one",
 					Type:       "string",
-			Default:    "nextval('abc'::regclass)",
-		},
-		{
-			Name:       "other",
 					IsNullable: false,
-			Type:       "int64",
-			Default:    "nextval",
+					Default:    `nextval('abc'::regclass)`,
+				},
+			},
+		},
+		"nodefault": {
+			Expect: "",
+			Pkey: &dbdrivers.PrimaryKey{
+				Name:    "pkey",
+				Columns: []string{"one"},
+			},
+			Columns: []dbdrivers.Column{
+				dbdrivers.Column{
+					Name:       "one",
+					Type:       "string",
+					IsNullable: false,
+					Default:    ``,
+				},
+			},
+		},
+		"nullable": {
+			Expect: "",
+			Pkey: &dbdrivers.PrimaryKey{
+				Name:    "pkey",
+				Columns: []string{"one"},
+			},
+			Columns: []dbdrivers.Column{
+				dbdrivers.Column{
+					Name:       "one",
+					Type:       "string",
+					IsNullable: true,
+					Default:    `nextval('abc'::regclass)`,
+				},
+			},
 		},
 	}
 
-	r = AutoIncPrimaryKey(cols, pkey)
-	if r != "" {
-		t.Errorf("Expected empty string, got %s", r)
+	for testName, test := range tests {
+		primaryKey := AutoIncPrimaryKey(test.Columns, test.Pkey)
+		if primaryKey != test.Expect {
+			t.Errorf("%s) wrong primary key, want: %q, got %q", testName, test.Expect, primaryKey)
 		}
-
-	cols = append(cols, dbdrivers.Column{
-		Name:       "auto",
-		IsNullable: false,
-		Type:       "int64",
-		Default:    "nextval('abc'::regclass)",
-	})
-
-	r = AutoIncPrimaryKey(cols, pkey)
-	if r != "auto" {
-		t.Errorf("Expected empty string, got %s", r)
 	}
 }