Add resource with heredoc to config load tests

This test reproduces the issue which is likely the root cause of #3840.
Test is currently failing with an "illegal character" message
corresponding with the location of the heredoc, which is also seen in
various acceptance tests for providers.

config/loader_test.go

@@ -45,6 +45,31 @@ func TestLoadFile_badType(t *testing.T) {
 	}
 }
 
+func TestLoadFileHeredoc(t *testing.T) {
+	c, err := LoadFile(filepath.Join(fixtureDir, "heredoc.tf"))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if c == nil {
+		t.Fatal("config should not be nil")
+	}
+
+	if c.Dir != "" {
+		t.Fatalf("bad: %#v", c.Dir)
+	}
+
+	actual := providerConfigsStr(c.ProviderConfigs)
+	if actual != strings.TrimSpace(heredocProvidersStr) {
+		t.Fatalf("bad:\n%s", actual)
+	}
+
+	actual = resourcesStr(c.Resources)
+	if actual != strings.TrimSpace(heredocResourcesStr) {
+		t.Fatalf("bad:\n%s", actual)
+	}
+}
+
 func TestLoadFileBasic(t *testing.T) {
 	c, err := LoadFile(filepath.Join(fixtureDir, "basic.tf"))
 	if err != nil {
@@ -532,6 +557,20 @@ func TestLoad_temporary_files(t *testing.T) {
 	}
 }
 
+const heredocProvidersStr = `
+aws
+  access_key
+  secret_key
+`
+
+const heredocResourcesStr = `
+aws_iam_policy[policy] (x1)
+  description
+  name
+  path
+  policy
+`
+
 const basicOutputsStr = `
 web_ip
   vars

config/test-fixtures/heredoc.tf

@@ -0,0 +1,24 @@
+provider "aws" {
+  access_key = "foo"
+  secret_key = "bar"
+}
+
+resource "aws_iam_policy" "policy" {
+    name = "test_policy"
+    path = "/"
+    description = "My test policy"
+    policy = <<EOF
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Action": [
+        "ec2:Describe*"
+      ],
+      "Effect": "Allow",
+      "Resource": "*"
+    }
+  ]
+}
+EOF
+}