feat: Add check for misspelled executable name command

server/events/comment_parser.go

@@ -149,7 +149,12 @@ func (e *CommentParser) Parse(rawComment string, vcsHost models.VCSHostType) Com
 
 	// Helpfully warn the user if they're using "terraform" instead of "atlantis"
 	if args[0] == "terraform" && e.ExecutableName != "terraform" {
-		return CommentParseResult{CommentResponse: fmt.Sprintf(DidYouMeanAtlantisComment, e.ExecutableName)}
+		return CommentParseResult{CommentResponse: fmt.Sprintf(DidYouMeanAtlantisComment, e.ExecutableName, "terraform")}
+	}
+
+	// Helpfully warn the user that the command might be misspelled
+	if utils.IsSimilarWord(args[0], e.ExecutableName) {
+		return CommentParseResult{CommentResponse: fmt.Sprintf(DidYouMeanAtlantisComment, e.ExecutableName, args[0])}
 	}
 
 	// Atlantis can be invoked using the name of the VCS host user we're
@@ -541,8 +546,8 @@ Use "{{ .ExecutableName }} [command] --help" for more information about a comman
 	"\n```"
 
 // DidYouMeanAtlantisComment is the comment we add to the pull request when
-// someone runs a command with terraform instead of atlantis.
-var DidYouMeanAtlantisComment = "Did you mean to use `%s` instead of `terraform`?"
+// someone runs a misspelled command or terraform instead of atlantis.
+var DidYouMeanAtlantisComment = "Did you mean to use `%s` instead of `%s`?"
 
 // UnlockUsage is the comment we add to the pull request when someone runs
 // `atlantis unlock` with flags.

server/events/comment_parser_test.go

@@ -251,7 +251,7 @@ func TestParse_DidYouMeanAtlantis(t *testing.T) {
 	}
 	for _, c := range comments {
 		r := commentParser.Parse(c, models.Github)
-		Assert(t, r.CommentResponse == fmt.Sprintf(events.DidYouMeanAtlantisComment, "atlantis"),
+		Assert(t, r.CommentResponse == fmt.Sprintf(events.DidYouMeanAtlantisComment, "atlantis", "terraform"),
 			"For comment %q expected CommentResponse==%q but got %q", c, events.DidYouMeanAtlantisComment, r.CommentResponse)
 	}
 }

server/utils/spellcheck.go

@@ -0,0 +1,17 @@
+package utils
+
+import (
+	"github.com/agext/levenshtein"
+)
+
+// IsSimilarWord calculates "The Levenshtein Distance" between two strings which
+// represents the minimum total cost of edits that would convert the first string
+// into the second. If the distance is less than 3, the word is considered misspelled.
+func IsSimilarWord(given string, suggestion string) bool {
+	dist := levenshtein.Distance(given, suggestion, nil)
+	if dist > 0 && dist < 3 {
+		return true
+	}
+
+	return false
+}

server/utils/spellcheck_test.go

@@ -0,0 +1,65 @@
+package utils_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/runatlantis/atlantis/server/utils"
+	. "github.com/runatlantis/atlantis/testing"
+)
+
+func Test_Spellcheck(t *testing.T) {
+	t.Log("check if given executable name is misspelled or just an unrelated word")
+
+	spellings := []struct {
+		Misspelled bool
+		Given      string
+		Want       string
+	}{
+		{
+			false,
+			"atlantis",
+			"atlantis",
+		},
+		{
+			false,
+			"maybe",
+			"atlantis",
+		},
+		{
+			false,
+			"atlantis-qa",
+			"atlantis-prod",
+		},
+		{
+			true,
+			"altantis",
+			"atlantis",
+		},
+		{
+			true,
+			"atlants",
+			"atlantis",
+		},
+		{
+			true,
+			"teraform",
+			"terraform",
+		},
+	}
+
+	for _, s := range spellings {
+		t.Run(fmt.Sprintf("given %s want %s", s.Given, s.Want), func(t *testing.T) {
+			isMisspelled := utils.IsSimilarWord(s.Given, s.Want)
+
+			if s.Misspelled {
+				Equals(t, isMisspelled, true)
+			}
+
+			if !s.Misspelled {
+				Equals(t, isMisspelled, false)
+			}
+		})
+	}
+
+}