Merge pull request #66 from lucapette/gmile-issue-56

Support range loops

README.md

@@ -224,8 +224,8 @@ $ echo "#{{ Int 0 100}} {{ Name }} <{{ Email }}>" | fakedata
 
 ### Generators
 
-All the generators listed under `fakedata -g` are available as functions into
-the templates. If the generator name is a single word, then it's available as a
+The generators listed under `fakedata -g` are available as functions into the
+templates. If the generator name is a single word, then it's available as a
 function with the same name capitalized (example: `int` becomes `Int`). If the
 generator name is composed by multiple words joined by dots, then the function
 name is again capitalized by the first letter of the word and joined together
@@ -276,17 +276,13 @@ returns a date between one year ago and today.
 
 ### Helpers
 
-Beside the generator functions, the `fakedata` template implementation provides
-a set of helper functions:
+Beside the generator functions, `fakedata` templates provide a set of helper
+functions:
 
 - `Loop`
 - `Odd`
 - `Even`
 
-When using a custom loop make sure to use `--limit 1`, otherwise the loop will
-run multiple times! Running a template with `{{ range Loop 5}}` and `--limit 5`
-will execute 25 times.
-
 If you need to create your own loop for advanced templates you can use the `{{
 Loop }}` function. This function takes a single integer as parameter which is
 the number of iterations. `Loop` has to be used with `range` e.g.
@@ -297,6 +293,14 @@ the number of iterations. `Loop` has to be used with `range` e.g.
 {{ end }}
 ```
 
+`Loop` can take a second argument, so that you can specify a range and
+`fakedata` will generate a random number of interations in that range. For
+example:
+
+```html
+{{ range Loop 1 5 }}42{{ end }}
+```
+
 In combination with `Loop` and `range` you can use `Odd` and `Even` to determine
 if the current iteration is odd or even. This is especially helpful when
 creating HTML tables:

integration/cli_test.go

@@ -258,6 +258,7 @@ var templateTests = []struct {
 	wantErr bool
 }{
 	{"simple.tmpl", "simple-template.golden", false},
+	{"loop.tmpl", "loop.golden", false},
 	{"broken.tmpl", "broken-template.golden", true},
 	{"unknown-function.tmpl", "unknown-function.golden", true},
 }

integration/fixtures/loop.tmpl

@@ -0,0 +1 @@
+{{range Loop 1 1}}42{{end}}

integration/golden/loop.golden

@@ -0,0 +1,10 @@
+42
+42
+42
+42
+42
+42
+42
+42
+42
+42

pkg/fakedata/template.go

@@ -2,6 +2,7 @@ package fakedata
 
 import (
 	"fmt"
+	"math/rand"
 	"os"
 	"strings"
 	"text/template"
@@ -17,7 +18,23 @@ func newTemplateFactory() *templateFactory {
 
 func (tf templateFactory) getFunctions() template.FuncMap {
 	funcMap := template.FuncMap{
-		"Loop": func(i int) []int { return make([]int, i) },
+		"Loop": func(minmax ...int) []int {
+			var n int
+
+			if len(minmax) == 1 {
+				n = minmax[0]
+			} else {
+				min := minmax[0]
+				max := minmax[1]
+				if min == max {
+					n = min
+				} else {
+					n = rand.Intn(max-min) + min
+				}
+			}
+
+			return make([]int, n)
+		},
 		"Odd":  func(i int) bool { return i%2 != 0 },
 		"Even": func(i int) bool { return i%2 == 0 },
 	}