Merge pull request #28202 from hashicorp/alisdair/fmt-multiline-value-expr-unwrap

cli: Fix fmt output for multi-line value exprs

command/fmt.go

@@ -366,7 +366,41 @@ func (c *FmtCommand) formatValueExpr(tokens hclwrite.Tokens) hclwrite.Tokens {
 	// "${
 	//    foo
 	// }"
-	return c.trimNewlines(inside)
+	trimmed := c.trimNewlines(inside)
+
+	// Finally, we check if the unwrapped expression is on multiple lines. If
+	// so, we ensure that it is surrounded by parenthesis to make sure that it
+	// parses correctly after unwrapping. This may be redundant in some cases,
+	// but is required for at least multi-line ternary expressions.
+	isMultiLine := false
+	hasLeadingParen := false
+	hasTrailingParen := false
+	for i, token := range trimmed {
+		switch {
+		case i == 0 && token.Type == hclsyntax.TokenOParen:
+			hasLeadingParen = true
+		case token.Type == hclsyntax.TokenNewline:
+			isMultiLine = true
+		case i == len(trimmed)-1 && token.Type == hclsyntax.TokenCParen:
+			hasTrailingParen = true
+		}
+	}
+	if isMultiLine && !(hasLeadingParen && hasTrailingParen) {
+		wrapped := make(hclwrite.Tokens, 0, len(trimmed)+2)
+		wrapped = append(wrapped, &hclwrite.Token{
+			Type:  hclsyntax.TokenOParen,
+			Bytes: []byte("("),
+		})
+		wrapped = append(wrapped, trimmed...)
+		wrapped = append(wrapped, &hclwrite.Token{
+			Type:  hclsyntax.TokenCParen,
+			Bytes: []byte(")"),
+		})
+
+		return wrapped
+	}
+
+	return trimmed
 }
 
 func (c *FmtCommand) formatTypeExpr(tokens hclwrite.Tokens) hclwrite.Tokens {

command/testdata/fmt/general_in.tf

@@ -42,3 +42,12 @@ resource "foo_instance" /* ... */ "baz" {
 
   provider "" {
 }
+
+locals {
+  name = "${contains(["foo"], var.my_var) ? "${var.my_var}-bar" :
+    contains(["baz"], var.my_var) ? "baz-${var.my_var}" :
+  file("ERROR: unsupported type ${var.my_var}")}"
+  wrapped = "${(var.my_var == null ? 1 :
+    var.your_var == null ? 2 :
+  3)}"
+}

command/testdata/fmt/general_out.tf

@@ -42,3 +42,12 @@ resource "foo_instance" "baz" {
 
 provider "" {
 }
+
+locals {
+  name = (contains(["foo"], var.my_var) ? "${var.my_var}-bar" :
+    contains(["baz"], var.my_var) ? "baz-${var.my_var}" :
+  file("ERROR: unsupported type ${var.my_var}"))
+  wrapped = (var.my_var == null ? 1 :
+    var.your_var == null ? 2 :
+  3)
+}