hclwrite: fix space being added between interpolated items

closes #65
- add missing edge case for two interpolated items next to each other
- add tests for both quote and heredoc cases

hclwrite/format.go

@@ -325,6 +325,10 @@ func spaceAfterToken(subject, before, after *Token) bool {
 	case subject.Type == hclsyntax.TokenCBrace && after.Type == hclsyntax.TokenTemplateSeqEnd:
 		return true
 
+	// Don't add spaces between interpolated items
+	case subject.Type == hclsyntax.TokenTemplateSeqEnd && after.Type == hclsyntax.TokenTemplateInterp:
+		return false
+
 	case tokenBracketChange(subject) > 0:
 		// No spaces after open brackets
 		return false

hclwrite/format_test.go

@@ -71,6 +71,10 @@ func TestFormat(t *testing.T) {
 			`a="hello ${~ name ~}"`,
 			`a = "hello ${~name~}"`,
 		},
+		{
+			`a="${b}${c}${ d } ${e}"`,
+			`a = "${b}${c}${d} ${e}"`,
+		},
 		{
 			`b{}`,
 			`b {}`,
@@ -500,6 +504,22 @@ foo {
   ${ { blahblahblah = x } }
 EOT
 }
+`,
+		},
+		{
+			`
+foo {
+  bar = <<-EOT
+  ${a}${b}${ c } ${d}
+EOT
+}
+`,
+			`
+foo {
+  bar = <<-EOT
+  ${a}${b}${c} ${d}
+EOT
+}
 `,
 		},
 	}