From ab6ed0df62d4d163eadbbe9777517afb822829d6 Mon Sep 17 00:00:00 2001
From: Arpad Ryszka <arpad.ryszka@gmail.com>
Date: Thu, 26 Nov 2020 16:02:43 +0100
Subject: [PATCH] setup CI

---
 .github/workflows/check.yaml |  8 ++++++++
 .gitignore                   |  1 +
 Makefile                     | 13 ++++++++-----
 fprint.go                    |  8 ++++++++
 sprint_test.go               |  6 +++---
 5 files changed, 28 insertions(+), 8 deletions(-)
 create mode 100644 .github/workflows/check.yaml

diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
new file mode 100644
index 0000000..9e6183f
--- /dev/null
+++ b/.github/workflows/check.yaml
@@ -0,0 +1,8 @@
+on: [push, pull_request]
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/setup-go@v2
+    - uses: actions/checkout@v2
+    - run: make ci-check
diff --git a/.gitignore b/.gitignore
index 223cec9..316958a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
+.bin
 .coverprofile
diff --git a/Makefile b/Makefile
index 8bb8f75..c09cdd4 100644
--- a/Makefile
+++ b/Makefile
@@ -3,10 +3,10 @@ SOURCES = $(shell find . -name "*.go")
 default: build
 
 build:
-	go build ./...
+	@go build ./...
 
 check:
-	go test -count 1 ./...
+	@go test -count 1 ./...
 
 imports:
 	@goimports -w $(SOURCES)
@@ -15,10 +15,13 @@ fmt:
 	@gofmt -w -s $(SOURCES)
 
 .coverprofile: $(SOURCES)
-	go test -count 1 -coverprofile .coverprofile
+	@go test -count 1 -coverprofile .coverprofile
 
 cover: .coverprofile
-	go tool cover -func .coverprofile
+	@go tool cover -func .coverprofile
 
 showcover: .coverprofile
-	go tool cover -html .coverprofile
+	@go tool cover -html .coverprofile
+
+check-fmt:
+	@! ( gofmt -s -l . | grep . )
diff --git a/fprint.go b/fprint.go
index c6dabbd..21c1949 100644
--- a/fprint.go
+++ b/fprint.go
@@ -65,6 +65,7 @@ func nodeLen(t int, n node) node {
 		return n
 	}
 
+	// measure all parts:
 	for i := range n.parts {
 		switch pt := n.parts[i].(type) {
 		case node:
@@ -76,6 +77,7 @@ func nodeLen(t int, n node) node {
 		}
 	}
 
+	// measure the unwrapped length:
 	for _, p := range n.parts {
 		switch pt := p.(type) {
 		case node:
@@ -94,6 +96,7 @@ func nodeLen(t int, n node) node {
 		}
 	}
 
+	// measure the wrapped and the fully wrapped length:
 	var w, f int
 	for _, p := range n.parts {
 		switch pt := p.(type) {
@@ -192,6 +195,7 @@ func wrapNode(t, cf0, c0, c1 int, n node) node {
 		return n
 	}
 
+	// otherwise, we need to wrap the node:
 	n.wrap = true
 
 	// We assume here that an str is always contained
@@ -203,6 +207,10 @@ func wrapNode(t, cf0, c0, c1 int, n node) node {
 		return n
 	}
 
+	// before iterating over the parts, take a copy of
+	// the available column width and modify only the
+	// copy, to support trackback.
+	//
 	cc0, cc1 := c0, c1
 	lastWrapperIndex := -1
 	var trackBack bool
diff --git a/sprint_test.go b/sprint_test.go
index 65a6aed..9c943c9 100644
--- a/sprint_test.go
+++ b/sprint_test.go
@@ -1004,9 +1004,9 @@ func TestLongString(t *testing.T) {
 
 func TestCyclicReferences(t *testing.T) {
 	t.Run("slice", func(t *testing.T) {
-		const expect = `r0=[]{r0}`
-		l := []interface{}{"foo"}
-		l[0] = l
+		const expect = `r0=[]{"foo", r0}`
+		l := []interface{}{"foo", "bar"}
+		l[1] = l
 		s := Sprint(l)
 		if s != expect {
 			t.Fatalf("expected: %s, got: %s", expect, s)