test: expand coverage across readers, writers, cmd, ui, diff and merge

Implements tests/_plans and previously deferred packages; updates plan
README with new coverage numbers.

pkg/writers/pgsql/column_comment_test.go

@@ -0,0 +1,110 @@
+package pgsql
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/writers"
+)
+
+func TestCurrentColumnHasDescription(t *testing.T) {
+	table := models.InitTable("users", "public")
+	c := models.InitColumn("Email", "users", "public")
+	c.Description = " the email "
+	table.Columns["Email"] = c
+
+	tests := []struct {
+		name  string
+		table *models.Table
+		col   *models.Column
+		want  bool
+	}{
+		{"nil table", nil, &models.Column{Name: "email", Description: "x"}, false},
+		{"match ignoring case and whitespace", table, &models.Column{Name: "email", Description: "the email"}, true},
+		{"different description", table, &models.Column{Name: "email", Description: "other"}, false},
+		{"column missing", table, &models.Column{Name: "age", Description: "x"}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := currentColumnHasDescription(tt.table, tt.col); got != tt.want {
+				t.Errorf("got %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestExecuteCommentColumn(t *testing.T) {
+	te, err := NewTemplateExecutor(false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := te.ExecuteCommentColumn(CommentColumnData{
+		SchemaName: "public", TableName: "users", ColumnName: "email", Comment: "it''s",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(got, "COMMENT ON COLUMN") || !strings.Contains(got, "public.users") ||
+		!strings.Contains(got, "email") || !strings.Contains(got, "IS 'it''s';") {
+		t.Errorf("unexpected output: %s", got)
+	}
+}
+
+func migrationWithColumnDescription(t *testing.T, currentDesc string, withCurrentCol bool) string {
+	t.Helper()
+	newDB := func(desc string, include bool) *models.Database {
+		db := models.InitDatabase("testdb")
+		s := models.InitSchema("public")
+		tbl := models.InitTable("users", "public")
+		id := models.InitColumn("id", "users", "public")
+		id.Type = "integer"
+		tbl.Columns["id"] = id
+		if include {
+			col := models.InitColumn("email", "users", "public")
+			col.Type = "text"
+			col.Description = desc
+			tbl.Columns["email"] = col
+		}
+		s.Tables = append(s.Tables, tbl)
+		db.Schemas = append(db.Schemas, s)
+		return db
+	}
+	model := newDB("it's the email", true)
+	current := newDB(currentDesc, withCurrentCol)
+
+	var buf bytes.Buffer
+	w, err := NewMigrationWriter(&writers.WriterOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	w.writer = &buf
+	if err := w.WriteMigration(model, current); err != nil {
+		t.Fatal(err)
+	}
+	return buf.String()
+}
+
+func TestWriteMigration_ColumnComments(t *testing.T) {
+	tests := []struct {
+		name        string
+		currentDesc string
+		withCol     bool
+		wantComment bool
+	}{
+		{"added", "", true, true},
+		{"changed", "old text", true, true},
+		{"unchanged", "it's the email", true, false},
+		{"new column", "", false, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			out := migrationWithColumnDescription(t, tt.currentDesc, tt.withCol)
+			has := strings.Contains(out, "COMMENT ON COLUMN") && strings.Contains(out, "it''s the email")
+			if has != tt.wantComment {
+				t.Errorf("comment emitted = %v, want %v\n%s", has, tt.wantComment, out)
+			}
+		})
+	}
+}