From c38782464a5eb1251a9146ab95814b868f72fe43 Mon Sep 17 00:00:00 2001
From: Cornelius Weig <22861411+corneliusweig@users.noreply.github.com>
Date: Tue, 18 Jun 2019 21:15:06 +0200
Subject: [PATCH] Simplify sync rules if `strip` is a suffix of `dest`

Signed-off-by: Cornelius Weig <22861411+corneliusweig@users.noreply.github.com>
---
 pkg/skaffold/schema/v1beta9/upgrade.go      | 30 +++++++++++++++++++--
 pkg/skaffold/schema/v1beta9/upgrade_test.go | 15 +++++------
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/pkg/skaffold/schema/v1beta9/upgrade.go b/pkg/skaffold/schema/v1beta9/upgrade.go
index 6cb4d63bd52..8ad00375ca1 100644
--- a/pkg/skaffold/schema/v1beta9/upgrade.go
+++ b/pkg/skaffold/schema/v1beta9/upgrade.go
@@ -102,16 +102,18 @@ func (config *SkaffoldConfig) convertSyncRules() [][]*next.SyncRule {
 			var syncRule *next.SyncRule
 			switch {
 			case compatibleSimplePattern.MatchString(src):
+				dest, strip := simplify(dest, compatibleSimplePattern.FindStringSubmatch(src)[1])
 				syncRule = &next.SyncRule{
 					Src:   src,
 					Dest:  dest,
-					Strip: compatibleSimplePattern.FindStringSubmatch(src)[1],
+					Strip: strip,
 				}
 			case strings.Contains(src, "***"):
+				dest, strip := simplify(dest, strings.Split(src, "***")[0])
 				syncRule = &next.SyncRule{
 					Src:   strings.Replace(src, "***", "**", -1),
 					Dest:  dest,
-					Strip: strings.Split(src, "***")[0],
+					Strip: strip,
 				}
 			default:
 				// Incompatible patterns contain `**` or glob directories.
@@ -135,3 +137,27 @@ func (config *SkaffoldConfig) convertSyncRules() [][]*next.SyncRule {
 	}
 	return newSync
 }
+
+// simplify dest and strip, if strip is a suffix of dest modulo a trailing `/`.
+func simplify(dest, strip string) (string, string) {
+	if strip == "" || strip == "/" || dest == "" {
+		return dest, strip
+	}
+
+	simpleStrip := strip
+	simpleDest := dest
+
+	if dest[len(dest)-1] != '/' {
+		dest = dest + "/"
+	}
+
+	if strings.HasSuffix(dest, strip) {
+		simpleDest = strings.TrimSuffix(dest, strings.TrimPrefix(strip, "/"))
+		simpleStrip = ""
+		if simpleDest == "" {
+			simpleDest = "."
+		}
+	}
+
+	return simpleDest, simpleStrip
+}
diff --git a/pkg/skaffold/schema/v1beta9/upgrade_test.go b/pkg/skaffold/schema/v1beta9/upgrade_test.go
index 7b356fa4ece..b9f38f78b3f 100644
--- a/pkg/skaffold/schema/v1beta9/upgrade_test.go
+++ b/pkg/skaffold/schema/v1beta9/upgrade_test.go
@@ -142,7 +142,7 @@ build:
   artifacts:
   - image: gcr.io/no-star-1
     sync:
-      '/public/A/B/a.html': /www
+      '/public/A/B/a.html': /public/A/B
   - image: gcr.io/no-star-2
     sync:
       '/b.html': /www
@@ -151,10 +151,10 @@ build:
       'c.html': /www
   - image: gcr.io/no-star-4
     sync:
-      'public/A/d.html': /www
+      'public/A/d.html': public/A/
   - image: gcr.io/single-star-1
     sync:
-      'public/*': /app
+      'public/*': /app/public/
   - image: gcr.io/single-star-2
     sync:
       'main*.js': /app
@@ -185,8 +185,7 @@ build:
     sync:
       manual:
       - src: /public/A/B/a.html
-        dest: /www
-        strip: /public/A/B/
+        dest: /
   - image: gcr.io/no-star-2
     sync:
       manual:
@@ -202,14 +201,12 @@ build:
     sync:
       manual:
       - src: public/A/d.html
-        dest: /www
-        strip: public/A/
+        dest: .
   - image: gcr.io/single-star-1
     sync:
       manual:
       - src: 'public/*'
-        dest: /app
-        strip: public/
+        dest: /app/
   - image: gcr.io/single-star-2
     sync:
       manual: