diff --git a/src/xatu/xatu_test.rs b/src/xatu/xatu_test.rs
index 010428d..b1cecc0 100644
--- a/src/xatu/xatu_test.rs
+++ b/src/xatu/xatu_test.rs
@@ -3,21 +3,14 @@ use std::path::{Path, PathBuf};
 use status::Code;
 use xatu::SourceFile;
 
-fn source_file(path: &str, source: &str) -> SourceFile {
+fn fixture_source(path: &str) -> SourceFile {
     SourceFile {
         path: PathBuf::from(path),
-        source: source.to_owned(),
+        source: std::fs::read_to_string(fixture_path(path)).expect("fixture should be readable"),
     }
 }
 
-fn testdata_source_file(path: &str) -> SourceFile {
-    source_file(
-        path,
-        &std::fs::read_to_string(testdata_path(path)).expect("fixture should be readable"),
-    )
-}
-
-fn testdata_path(path: &str) -> PathBuf {
+fn fixture_path(path: &str) -> PathBuf {
     if Path::new(path).exists() {
         return PathBuf::from(path);
     }
@@ -28,9 +21,14 @@ fn testdata_path(path: &str) -> PathBuf {
     runfiles.join(workspace).join("src/xatu").join(path)
 }
 
+fn only_diagnostic(report: &xatu::Report) -> &xatu::Diagnostic {
+    assert_eq!(report.diagnostics.len(), 1);
+    &report.diagnostics[0]
+}
+
 #[test]
 fn future_sight_reports_clean_sources_as_clean() {
-    let report = xatu::future_sight(vec![testdata_source_file("testdata/clean.nix")])
+    let report = xatu::future_sight(vec![fixture_source("testdata/clean.nix")])
         .expect("fixture should parse");
 
     assert!(report.is_clean());
@@ -38,59 +36,47 @@ fn future_sight_reports_clean_sources_as_clean() {
 
 #[test]
 fn future_sight_rejects_parse_errors() {
-    let error = xatu::future_sight(vec![source_file("invalid.nix", "{\n")])
-        .expect_err("fixture should fail to parse");
+    let error = xatu::future_sight(vec![SourceFile {
+        path: PathBuf::from("invalid.nix"),
+        source: "{\n".to_owned(),
+    }])
+    .expect_err("fixture should fail to parse");
 
     assert_eq!(error.code(), Code::FailedPrecondition);
 }
 
 #[test]
 fn future_sight_reports_deprecated_to_path_ident_findings() {
-    let report = xatu::future_sight(vec![source_file(
-        "deprecated_to_path_ident.nix",
-        "toPath x\n",
-    )])
+    let report = xatu::future_sight(vec![SourceFile {
+        path: PathBuf::from("deprecated_to_path_ident.nix"),
+        source: "toPath x\n".to_owned(),
+    }])
     .expect("fixture should parse");
 
-    assert_eq!(report.diagnostics.len(), 1);
+    let diagnostic = only_diagnostic(&report);
 
-    let diagnostic = &report.diagnostics[0];
-    assert_eq!(
-        report.files.get(diagnostic.file_id).path,
-        PathBuf::from("deprecated_to_path_ident.nix"),
-    );
     assert_eq!(diagnostic.finding.rule_id, "deprecated_to_path");
 }
 
 #[test]
 fn future_sight_reports_deprecated_to_path_select_findings() {
-    let report = xatu::future_sight(vec![source_file(
-        "deprecated_to_path_select.nix",
-        "builtins.toPath x\n",
-    )])
+    let report = xatu::future_sight(vec![SourceFile {
+        path: PathBuf::from("deprecated_to_path_select.nix"),
+        source: "builtins.toPath x\n".to_owned(),
+    }])
     .expect("fixture should parse");
 
-    assert_eq!(report.diagnostics.len(), 1);
+    let diagnostic = only_diagnostic(&report);
 
-    let diagnostic = &report.diagnostics[0];
-    assert_eq!(
-        report.files.get(diagnostic.file_id).path,
-        PathBuf::from("deprecated_to_path_select.nix"),
-    );
     assert_eq!(diagnostic.finding.rule_id, "deprecated_to_path");
 }
 
 #[test]
 fn future_sight_reports_empty_inherit_findings() {
-    let report = xatu::future_sight(vec![testdata_source_file("testdata/empty_inherit.nix")])
+    let report = xatu::future_sight(vec![fixture_source("testdata/empty_inherit.nix")])
         .expect("fixture should parse");
 
-    assert_eq!(report.diagnostics.len(), 1);
+    let diagnostic = only_diagnostic(&report);
 
-    let diagnostic = &report.diagnostics[0];
-    assert_eq!(
-        report.files.get(diagnostic.file_id).path,
-        PathBuf::from("testdata/empty_inherit.nix"),
-    );
     assert_eq!(diagnostic.finding.rule_id, "empty_inherit");
 }