fix: config fixes for Windows

- Update the default config file to use `more` instead of `less` as the
  default pager, in order to support Windows out-of-the-box. (#655, #665).

- Use `terminal` Chroma formatter (rather than `terminal16m`) in order
  to accommodate less capable terminal emulators like `cmd.exe` by
  default. Similarly, default to `colorize: false` in configs (changed
  from `true`) (#665).

- Comment out default `style` in order to avoid printing ANSI color
  codes into terminals without color support (#665)

- Attempt to intelligently choose a default editor, rather than rely on
  a hard-coded `vim` in the configs. This should make it easier to use
  `cheat` immediately without needing to specify configs. It should also
  improve `cheat`'s Windows compatibility. (#665)

internal/config/config.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 
 	cp "github.com/cheat/cheat/internal/cheatpath"
@@ -98,8 +100,22 @@ func New(opts map[string]interface{}, confPath string, resolve bool) (Config, er
 			conf.Editor = os.Getenv("VISUAL")
 		} else if os.Getenv("EDITOR") != "" {
 			conf.Editor = os.Getenv("EDITOR")
+		} else if runtime.GOOS == "windows" {
+			conf.Editor = "notepad"
 		} else {
-			return Config{}, fmt.Errorf("no editor set")
+			// try to fall back to `nano`
+			path, err := exec.LookPath("nano")
+			if err != nil {
+				return Config{}, fmt.Errorf("failed to locate nano: %s", err)
+			}
+
+			// use `nano` if we found it
+			if path != "" {
+				conf.Editor = "nano"
+				// otherwise, give up
+			} else {
+				return Config{}, fmt.Errorf("no editor set")
+			}
 		}
 	}
 
@@ -110,12 +126,13 @@ func New(opts map[string]interface{}, confPath string, resolve bool) (Config, er
 
 	// if a chroma formatter was not provided, set a default
 	if conf.Formatter == "" {
-		conf.Formatter = "terminal16m"
+		conf.Formatter = "terminal"
 	}
 
-	// if a pager was not provided, set a default
-	if strings.TrimSpace(conf.Pager) == "" {
-		conf.Pager = ""
+	// attempt to fall back to `PAGER` if a pager is not specified in configs
+	conf.Pager = strings.TrimSpace(conf.Pager)
+	if conf.Pager == "" && os.Getenv("PAGER") != "" {
+		conf.Pager = os.Getenv("PAGER")
 	}
 
 	return conf, nil

internal/config/config_test.go

@@ -85,8 +85,8 @@ func TestEmptyEditor(t *testing.T) {
 
 	// initialize a config
 	conf, err := New(map[string]interface{}{}, mock.Path("conf/empty.yml"), false)
-	if err == nil {
-		t.Errorf("failed to return an error on empty editor")
+	if err != nil {
+		t.Errorf("failed to initialize test: %v", err)
 	}
 
 	// set editor, and assert that it is respected