bracket-push: create test case generator

exercises/bracket-push/.meta/gen.go

@@ -0,0 +1,49 @@
+// +build ignore
+
+package main
+
+import (
+	"log"
+	"text/template"
+
+	"../../../gen"
+)
+
+func main() {
+	t, err := template.New("").Parse(tmpl)
+	if err != nil {
+		log.Fatal(err)
+	}
+	var j js
+	if err := gen.Gen("bracket-push", &j, t); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// The JSON structure we expect to be able to unmarshal into
+type js struct {
+	Cases []struct {
+		Description string
+		Input       string
+		Expected    bool
+	}
+}
+
+// template applied to above data structure generates the Go test cases
+var tmpl = `package brackets
+
+{{.Header}}
+
+type bracketTest struct {
+	input       string
+	expected    bool
+}
+
+var testCases = []bracketTest {
+{{range .J.Cases}}{
+	// {{.Description}}
+	{{printf "%q" .Input}},
+	{{.Expected}},
+},
+{{end}}}
+`

exercises/bracket-push/bracket_push_test.go

@@ -4,49 +4,7 @@ import (
 	"testing"
 )
 
-const targetTestVersion = 4
-
-var testCases = []struct {
-	input    string
-	expected bool
-}{
-	{
-		input:    "",
-		expected: true,
-	},
-	{
-		input:    "{}",
-		expected: true,
-	},
-	{
-		input:    "{{",
-		expected: false,
-	},
-	{
-		input:    "}{",
-		expected: false,
-	},
-	{
-		input:    "{}[]",
-		expected: true,
-	},
-	{
-		input:    "{[]}",
-		expected: true,
-	},
-	{
-		input:    "{[}]",
-		expected: false,
-	},
-	{
-		input:    "{[)][]}",
-		expected: false,
-	},
-	{
-		input:    "{[]([()])}",
-		expected: true,
-	},
-}
+const targetTestVersion = 5
 
 func TestTestVersion(t *testing.T) {
 	if testVersion != targetTestVersion {

exercises/bracket-push/cases_test.go

@@ -0,0 +1,83 @@
+package brackets
+
+// Source: exercism/x-common
+// Commit: 855c591 bracket-push: add test case (#747)
+// x-common version: 1.1.0
+
+type bracketTest struct {
+	input    string
+	expected bool
+}
+
+var testCases = []bracketTest{
+	{
+		// paired square brackets
+		"[]",
+		true,
+	},
+	{
+		// empty string
+		"",
+		true,
+	},
+	{
+		// unpaired brackets
+		"[[",
+		false,
+	},
+	{
+		// wrong ordered brackets
+		"}{",
+		false,
+	},
+	{
+		// wrong closing bracket
+		"{]",
+		false,
+	},
+	{
+		// paired with whitespace
+		"{ }",
+		true,
+	},
+	{
+		// simple nested brackets
+		"{[]}",
+		true,
+	},
+	{
+		// several paired brackets
+		"{}[]",
+		true,
+	},
+	{
+		// paired and nested brackets
+		"([{}({}[])])",
+		true,
+	},
+	{
+		// unopened closing brackets
+		"{[)][]}",
+		false,
+	},
+	{
+		// unpaired and nested brackets
+		"([{])",
+		false,
+	},
+	{
+		// paired and wrong nested brackets
+		"[({]})",
+		false,
+	},
+	{
+		// math expression
+		"(((185 + 223.85) * 15) - 543)/2",
+		true,
+	},
+	{
+		// complex latex expression
+		"\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)",
+		true,
+	},
+}

exercises/bracket-push/example.go

@@ -1,18 +1,15 @@
 package brackets
 
-import (
-	"fmt"
-)
-
 // testVersion shows the version of the exercise.
-const testVersion = 4
+const testVersion = 5
 
 type bracketKind int
 
 const (
 	kindParen  bracketKind = iota
 	kindSquare bracketKind = iota
 	kindBrace  bracketKind = iota
+	kindOther  bracketKind = iota
 )
 
 // Whether a bracket is an opening or closing bracket
@@ -33,9 +30,9 @@ type charInfo struct {
 func Bracket(input string) (bool, error) {
 	var stack []bracketKind
 	for _, char := range input {
-		ci, err := info(char)
-		if err != nil {
-			return false, err
+		ci := info(char)
+		if ci.kind == kindOther {
+			continue
 		}
 		if ci.form == formOpen {
 			stack = append(stack, ci.kind)
@@ -52,21 +49,21 @@ func Bracket(input string) (bool, error) {
 	return len(stack) == 0, nil
 }
 
-func info(char rune) (charInfo, error) {
+func info(char rune) charInfo {
 	switch char {
 	case '(':
-		return charInfo{kind: kindParen, form: formOpen}, nil
+		return charInfo{kind: kindParen, form: formOpen}
 	case '[':
-		return charInfo{kind: kindSquare, form: formOpen}, nil
+		return charInfo{kind: kindSquare, form: formOpen}
 	case '{':
-		return charInfo{kind: kindBrace, form: formOpen}, nil
+		return charInfo{kind: kindBrace, form: formOpen}
 	case ')':
-		return charInfo{kind: kindParen, form: formClose}, nil
+		return charInfo{kind: kindParen, form: formClose}
 	case ']':
-		return charInfo{kind: kindSquare, form: formClose}, nil
+		return charInfo{kind: kindSquare, form: formClose}
 	case '}':
-		return charInfo{kind: kindBrace, form: formClose}, nil
+		return charInfo{kind: kindBrace, form: formClose}
 	default:
-		return charInfo{}, fmt.Errorf("Unknown bracket %v", char)
+		return charInfo{kind: kindOther}
 	}
 }