feat: add basic string function to template (#1232)

internal/tmpl/tmpl.go

@@ -108,9 +108,13 @@ func (t *Template) Apply(s string) (string, error) {
 	tmpl, err := template.New("tmpl").
 		Option("missingkey=error").
 		Funcs(template.FuncMap{
+			"replace": strings.ReplaceAll,
 			"time": func(s string) string {
 				return time.Now().UTC().Format(s)
 			},
+			"tolower": strings.ToLower,
+			"toupper": strings.ToUpper,
+			"trim":    strings.TrimSpace,
 		}).
 		Parse(s)
 	if err != nil {

internal/tmpl/tmpl_test.go

@@ -154,23 +154,48 @@ func TestFuncMap(t *testing.T) {
 	for _, tc := range []struct {
 		Template string
 		Name     string
+		Expected string
 	}{
+		{
+			Template: `{{ replace "v1.24" "v" "" }}`,
+			Name:     "replace",
+			Expected: "1.24",
+		},
 		{
 			Template: `{{ time "2006-01-02" }}`,
-			Name:     "YYYY-MM-DD",
+			Name:     "time YYYY-MM-DD",
 		},
 		{
 			Template: `{{ time "01/02/2006" }}`,
-			Name:     "MM/DD/YYYY",
+			Name:     "time MM/DD/YYYY",
 		},
 		{
 			Template: `{{ time "01/02/2006" }}`,
-			Name:     "MM/DD/YYYY",
+			Name:     "time MM/DD/YYYY",
+		},
+		{
+			Template: `{{ tolower "TEST" }}`,
+			Name:     "tolower",
+			Expected: "test",
+		},
+		{
+			Template: `{{ toupper "test" }}`,
+			Name:     "toupper",
+			Expected: "TEST",
+		},
+		{
+			Template: `{{ trim " test " }}`,
+			Name:     "trim",
+			Expected: "test",
 		},
 	} {
 		out, err := New(ctx).Apply(tc.Template)
 		assert.NoError(t, err)
-		assert.NotEmpty(t, out)
+		if tc.Expected != "" {
+			assert.Equal(t, tc.Expected, out)
+		} else {
+			assert.NotEmpty(t, out)
+		}
 	}
 }
 

www/content/templates.md

@@ -42,15 +42,19 @@ may have some extra fields:
 
 On all fields, you have these available functions:
 
-|        Usage        |               Description                |
-| :-----------------: | :--------------------------------------: |
-| `time "01/02/2006"` | current UTC time in the specified format |
+|        Usage            |               Description                                                                                |
+| :--------------------:  | :----------------------------------------------------------------------------------:                     |
+| `replace "v1.2" "v" ""` | replaces all macthes. See [ReplaceAll](https://golang.org/pkg/strings/#ReplaceAll)                       |
+| `time "01/02/2006"`     | current UTC time in the specified format                                                                 |
+| `tolower "V1.2"`        | makes input string lowercase. See [ToLower](https://golang.org/pkg/strings/#ToLower)                     |
+| `toupper "v1.2"`        | makes input string uppercase. See [ToUpper](https://golang.org/pkg/strings/#ToUpper)                     |
+| `trim " v1.2  "`        | removes all leading and trailing white space. See [TrimSpace](https://golang.org/pkg/strings/#TrimSpace) |
 
 With all those fields, you may be able to compose the name of your artifacts
 pretty much the way you want:
 
 ```yaml
-example_template: '{{ .ProjectName }}_{{ .Env.USER }}_{{ time "2006" }}'
+example_template: '{{ tolower .ProjectName }}_{{ .Env.USER }}_{{ time "2006" }}'
 ```
 
 For example, if you want to add the go version to some artifact: