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/template/formatters_test.go

@@ -0,0 +1,118 @@
+package template
+
+import (
+	"math"
+	"strings"
+	"testing"
+)
+
+func TestToJSON(t *testing.T) {
+	if got := ToJSON(map[string]int{"a": 1}); got != `{"a":1}` {
+		t.Errorf("got %q", got)
+	}
+	if got := ToJSON(nil); got != "null" {
+		t.Errorf("nil: %q", got)
+	}
+	if got := ToJSON(math.Inf(1)); !strings.HasPrefix(got, `{"error": "failed to marshal`) {
+		t.Errorf("marshal failure: %q", got)
+	}
+}
+
+func TestToJSONPretty(t *testing.T) {
+	got := ToJSONPretty(map[string]int{"a": 1}, "  ")
+	if got != "{\n  \"a\": 1\n}" {
+		t.Errorf("got %q", got)
+	}
+	if got := ToJSONPretty(make(chan int), "  "); !strings.HasPrefix(got, `{"error"`) {
+		t.Errorf("marshal failure: %q", got)
+	}
+}
+
+func TestToYAML(t *testing.T) {
+	if got := ToYAML(map[string]int{"a": 1}); got != "a: 1\n" {
+		t.Errorf("got %q", got)
+	}
+	if got := ToYAML(make(chan int)); !strings.HasPrefix(got, "error: failed to marshal") {
+		// yaml.v3 panics-recovers into an error for unsupported types
+		t.Errorf("marshal failure: %q", got)
+	}
+}
+
+func TestIndent(t *testing.T) {
+	tests := []struct {
+		in     string
+		spaces int
+		want   string
+	}{
+		{"", 4, ""},
+		{"a", 2, "  a"},
+		{"a\nb", 2, "  a\n  b"},
+		{"a\n\nb", 2, "  a\n\n  b"},
+		{"a", 0, "a"},
+	}
+	for _, tt := range tests {
+		if got := Indent(tt.in, tt.spaces); got != tt.want {
+			t.Errorf("Indent(%q,%d) = %q, want %q", tt.in, tt.spaces, got, tt.want)
+		}
+	}
+	if got := IndentWith("", ">"); got != "" {
+		t.Errorf("IndentWith empty: %q", got)
+	}
+	if got := IndentWith("a\n\nb", "> "); got != "> a\n\n> b" {
+		t.Errorf("IndentWith: %q", got)
+	}
+}
+
+func TestEscape(t *testing.T) {
+	if got := Escape("a\"b\\c\nd\re\tf"); got != `a\"b\\c\nd\re\tf` {
+		t.Errorf("got %q", got)
+	}
+	if got := Escape(""); got != "" {
+		t.Errorf("empty: %q", got)
+	}
+	if got := EscapeQuotes(`a"b'c`); got != `a\"b\'c` {
+		t.Errorf("EscapeQuotes: %q", got)
+	}
+}
+
+func TestComment(t *testing.T) {
+	tests := []struct {
+		name, in, style, want string
+	}{
+		{"empty", "", "//", ""},
+		{"slashes", "a\nb", "//", "// a\n// b"},
+		{"hash", "a", "#", "# a"},
+		{"sql", "a\nb", "--", "-- a\n-- b"},
+		{"block single", "a", "/* */", "/* a */"},
+		{"block single alt", "a", "/**/", "/* a */"},
+		{"block multi", "a\nb", "/* */", "/*\n * a\n * b\n */"},
+		{"default", "a", "weird", "// a"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Comment(tt.in, tt.style); got != tt.want {
+				t.Errorf("got %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestQuoteUnquote(t *testing.T) {
+	if got := QuoteString("a"); got != `"a"` {
+		t.Errorf("QuoteString: %q", got)
+	}
+	tests := []struct{ in, want string }{
+		{`"a"`, "a"},
+		{`'a'`, "a"},
+		{`""`, ""},
+		{`"a'`, `"a'`},
+		{`a`, `a`},
+		{`"`, `"`},
+		{"", ""},
+	}
+	for _, tt := range tests {
+		if got := UnquoteString(tt.in); got != tt.want {
+			t.Errorf("UnquoteString(%q) = %q, want %q", tt.in, got, tt.want)
+		}
+	}
+}