Add path_join function to the stdlib

CHANGELOG.md

@@ -10,6 +10,10 @@ internal API changes are not present.
 Main (unreleased)
 -----------------
 
+### Features
+
+- Add the function `path_join` to the stdlib. (@wildum)
+
 v1.1.0-rc.0
 -----------
 

docs/sources/reference/stdlib/path_join.md

@@ -0,0 +1,20 @@
+---
+canonical: https://grafana.com/docs/alloy/latest/reference/stdlib/path_join/
+description: Learn about path_join
+title: path_join
+---
+
+# path_join
+
+`path_join` joins any number of path elements into a single path, separating them with an OS specific separator.
+
+## Examples
+
+```alloy
+> path_join("this/is", "a/path")
+"this/is/a/path"
+> path_join("empty/path", "")
+"empty/path"
+> join("foo/", "/bar/", "foo/bar", "foo")
+"foo/bar/foo/bar/foo"
+```

syntax/internal/stdlib/stdlib.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/grafana/alloy/syntax/alloytypes"
@@ -129,4 +130,5 @@ var Identifiers = map[string]interface{}{
 	"trim_prefix": strings.TrimPrefix,
 	"trim_suffix": strings.TrimSuffix,
 	"trim_space":  strings.TrimSpace,
+	"path_join":   filepath.Join,
 }

syntax/vm/vm_stdlib_test.go

@@ -163,6 +163,7 @@ func TestStdlib_StringFunc(t *testing.T) {
 		{"trim2", `trim("   hello! world.!  ", "! ")`, "hello! world."},
 		{"trim_prefix", `trim_prefix("helloworld", "hello")`, "world"},
 		{"trim_suffix", `trim_suffix("helloworld", "world")`, "hello"},
+		{"path_join", `path_join("this/is", "a/path")`, "this/is/a/path"},
 	}
 
 	for _, tc := range tt {