Expose "unparse", FormatNode and RawAST (#710)

* Export FormatNode so external users can pretty print an AST

Signed-off-by: Tom Wilkie <tom@grafana.com>

* Expose RawAST function.

Signed-off-by: Tom Wilkie <tom@grafana.com>

* Add comment

Signed-off-by: Tom Wilkie <tom@grafana.com>

---------

Signed-off-by: Tom Wilkie <tom@grafana.com>
Co-authored-by: Tom Wilkie <tom@grafana.com>

Author: charleskorn

formatter/formatter.go

@@ -4,7 +4,11 @@
 // customized using formatter.Options.
 package formatter
 
-import "github.com/google/go-jsonnet/internal/formatter"
+import (
+	"github.com/google/go-jsonnet/ast"
+	"github.com/google/go-jsonnet/internal/formatter"
+	"github.com/google/go-jsonnet/internal/parser"
+)
 
 // StringStyle controls how the reformatter rewrites string literals.
 // Strings that contain a ' or a " use the optimal syntax to avoid escaping
@@ -46,3 +50,14 @@ func DefaultOptions() Options {
 func Format(filename string, input string, options Options) (string, error) {
 	return formatter.Format(filename, input, options)
 }
+
+// FormatNode returns code that is equivalent to its input but better formatted
+// according to the given options.
+func FormatNode(node ast.Node, finalFodder ast.Fodder, options Options) (string, error) {
+	return formatter.FormatNode(node, finalFodder, options)
+}
+
+// SnippetToRawAST parses a snippet and returns the resulting AST.
+func SnippetToRawAST(filename string, snippet string) (ast.Node, ast.Fodder, error) {
+	return parser.SnippetToRawAST(ast.DiagnosticFileName(filename), "", snippet)
+}

internal/formatter/jsonnetfmt.go

@@ -152,6 +152,12 @@ func Format(filename string, input string, options Options) (string, error) {
 		return "", err
 	}
 
+	return FormatNode(node, finalFodder, options)
+}
+
+// FormatNode returns code that is equivalent to its input but better formatted
+// according to the given options.
+func FormatNode(node ast.Node, finalFodder ast.Fodder, options Options) (string, error) {
 	// Passes to enforce style on the AST.
 	if options.SortImports {
 		SortImports(&node)