tiltfile: add fuzzy matching suggestions to docker_build (#1178)

internal/tiltfile/build_index.go

@@ -2,8 +2,10 @@ package tiltfile
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/docker/distribution/reference"
+	"github.com/schollz/closestmatch"
 	"github.com/windmilleng/tilt/internal/model"
 )
 
@@ -15,13 +17,17 @@ type buildIndex struct {
 	taggedImages   map[string]*dockerImage
 	nameOnlyImages map[string]*dockerImage
 	byTargetID     map[model.TargetID]*dockerImage
+
+	consumedImageNames   []string
+	consumedImageNameMap map[string]bool
 }
 
 func newBuildIndex() *buildIndex {
 	return &buildIndex{
-		taggedImages:   make(map[string]*dockerImage),
-		nameOnlyImages: make(map[string]*dockerImage),
-		byTargetID:     make(map[model.TargetID]*dockerImage),
+		taggedImages:         make(map[string]*dockerImage),
+		nameOnlyImages:       make(map[string]*dockerImage),
+		byTargetID:           make(map[model.TargetID]*dockerImage),
+		consumedImageNameMap: make(map[string]bool),
 	}
 }
 
@@ -63,6 +69,11 @@ func (idx *buildIndex) findBuilderByID(id model.TargetID) *dockerImage {
 // Check to see if we have a build target for that image,
 // and mark that build target as consumed by an larger target.
 func (idx *buildIndex) findBuilderForConsumedImage(ref reference.Named) *dockerImage {
+	if !idx.consumedImageNameMap[ref.Name()] {
+		idx.consumedImageNameMap[ref.Name()] = true
+		idx.consumedImageNames = append(idx.consumedImageNames, ref.Name())
+	}
+
 	refTagged, hasTag := ref.(reference.NamedTagged)
 	if hasTag {
 		key := fmt.Sprintf("%s:%s", ref.Name(), refTagged.Tag())
@@ -85,7 +96,18 @@ func (idx *buildIndex) findBuilderForConsumedImage(ref reference.Named) *dockerI
 func (idx *buildIndex) assertAllMatched() error {
 	for _, image := range idx.images {
 		if !image.matched {
-			return fmt.Errorf("image %v is not used in any resource", image.ref.String())
+			bagSizes := []int{2, 3, 4}
+			cm := closestmatch.New(idx.consumedImageNames, bagSizes)
+			matchLines := []string{}
+			for i, match := range cm.ClosestN(image.ref.Name(), 3) {
+				if i == 0 {
+					matchLines = append(matchLines, "Did you mean:")
+				}
+				matchLines = append(matchLines, fmt.Sprintf(" - %s", match))
+			}
+
+			return fmt.Errorf("image %v is not used in any resource. %s",
+				image.ref.String(), strings.Join(matchLines, "\n"))
 		}
 	}
 	return nil

internal/tiltfile/tiltfile_test.go

@@ -1237,6 +1237,19 @@ k8s_yaml('foo.yaml')
 	}, f.imageTargetNames(m))
 }
 
+func TestImageRefSuggestion(t *testing.T) {
+	f := newFixture(t)
+	defer f.TearDown()
+
+	f.setupFoo()
+	f.file("Tiltfile", `
+docker_build('gcr.typo.io/foo', 'foo')
+k8s_resource('foo', 'foo.yaml')
+`)
+
+	f.loadErrString("Did you mean:\n - gcr.io/foo")
+}
+
 type fixture struct {
 	ctx context.Context
 	t   *testing.T