[librsvg: 3/4] Add `test_compare_render_output!` macro for filter ref tests

[Federico Mena Quintero <federico src gnome org>]

commit 60ec5b659285fe269eaf658e52fff5f28bd34abd
Author: John Ledbetter <john ledbetter gmail com>
Date:   Wed May 12 10:41:02 2021 -0400

    Add `test_compare_render_output!` macro for filter ref tests
    
    `test_compare_render_output!` takes three arguments:
    * The test name, used for defining the test fn and for error output
    * The test SVG string
    * A reference SVG string to compare against.
    
    This reduces some copy-paste duplication in the filter function tests.

 tests/src/filters.rs | 229 ++++++++++++++-------------------------------------
 1 file changed, 60 insertions(+), 169 deletions(-)
---
diff --git a/tests/src/filters.rs b/tests/src/filters.rs
index 61e89927..c283c74e 100644
--- a/tests/src/filters.rs
+++ b/tests/src/filters.rs
@@ -3,6 +3,45 @@ use cairo;
 use crate::reference_utils::{Compare, Evaluate, Reference};
 use crate::utils::{load_svg, render_document, SurfaceSize};
 
+macro_rules! test_compare_render_output {
+    ($test_name:ident, $test:expr, $reference:expr $(,)?) => {
+        #[test]
+        fn $test_name() {
+            let svg = load_svg($test).unwrap();
+            let output_surf = render_document(
+                &svg,
+                SurfaceSize(400, 400),
+                |_| (),
+                cairo::Rectangle {
+                    x: 0.0,
+                    y: 0.0,
+                    width: 400.0,
+                    height: 400.0,
+                },
+            )
+            .unwrap();
+
+            let reference = load_svg($reference).unwrap();
+            let reference_surf = render_document(
+                &reference,
+                SurfaceSize(400, 400),
+                |_| (),
+                cairo::Rectangle {
+                    x: 0.0,
+                    y: 0.0,
+                    width: 400.0,
+                    height: 400.0,
+                },
+            )
+            .unwrap();
+
+            Reference::from_surface(reference_surf.into_image_surface().unwrap())
+                .compare(&output_surf)
+                .evaluate(&output_surf, stringify!($test_name));
+        }
+    };
+}
+
 #[test]
 fn invalid_filter_reference_cancels_filter_chain() {
     // The <rect> has a filter chain with two URLs listed, but the second one doesn't resolve.
@@ -99,33 +138,14 @@ fn non_filter_reference_cancels_filter_chain() {
         .evaluate(&output_surf, "non_filter_reference_cancels_filter_chain");
 }
 
-#[test]
-fn blur_filter_func() {
-    // Create an element with a filter function, and compare it to the
-    // supposed equivalent using the <filter> element.
-    let svg = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+test_compare_render_output!(
+    blur_filter_func,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="blur(5)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let output_surf = render_document(
-        &svg,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    let reference = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <defs>
     <filter id="filter">
@@ -136,54 +156,17 @@ fn blur_filter_func() {
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="url(#filter)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let reference_surf = render_document(
-        &reference,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    Reference::from_surface(reference_surf.into_image_surface().unwrap())
-        .compare(&output_surf)
-        .evaluate(&output_surf, "blur_filter_func");
-}
+);
 
-#[test]
-fn opacity_filter_func() {
-    // Create an element with a filter function, and compare it to the
-    // supposed equivalent using the <filter> element.
-    let svg = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+test_compare_render_output!(
+opacity_filter_func,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <rect x="100" y="100" width="200" height="200" fill="red"/>
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="opacity(0.75)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let output_surf = render_document(
-        &svg,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    let reference = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <defs>
     <filter id="filter">
@@ -196,54 +179,17 @@ fn opacity_filter_func() {
   <rect x="100" y="100" width="200" height="200" fill="red"/>
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="url(#filter)"/>
 </svg>
-"##,
-    ).unwrap();
+"##
+);
 
-    let reference_surf = render_document(
-        &reference,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    Reference::from_surface(reference_surf.into_image_surface().unwrap())
-        .compare(&output_surf)
-        .evaluate(&output_surf, "opacity_filter_func");
-}
-
-#[test]
-fn saturate_filter_func() {
-    // Create an element with a filter function, and compare it to the
-    // supposed equivalent using the <filter> element.
-    let svg = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+test_compare_render_output!(
+    saturate_filter_func,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="saturate(0.75)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let output_surf = render_document(
-        &svg,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    let reference = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <defs>
     <filter id="filter">
@@ -254,53 +200,16 @@ fn saturate_filter_func() {
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="url(#filter)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let reference_surf = render_document(
-        &reference,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    Reference::from_surface(reference_surf.into_image_surface().unwrap())
-        .compare(&output_surf)
-        .evaluate(&output_surf, "saturate_filter_func");
-}
+);
 
-#[test]
-fn sepia_filter_func() {
-    // Create an element with a filter function, and compare it to the
-    // supposed equivalent using the <filter> element.
-    let svg = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+test_compare_render_output!(
+    sepia_filter_func,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="sepia(0.75)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let output_surf = render_document(
-        &svg,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    let reference = load_svg(
-        br##"<?xml version="1.0" encoding="UTF-8"?>
+    br##"<?xml version="1.0" encoding="UTF-8"?>
 <svg version="1.1" xmlns="http://www.w3.org/2000/svg"; xmlns:xlink="http://www.w3.org/1999/xlink"; width="400" 
height="400">
   <defs>
     <filter id="filter">
@@ -315,22 +224,4 @@ fn sepia_filter_func() {
   <rect x="100" y="100" width="200" height="200" fill="lime" filter="url(#filter)"/>
 </svg>
 "##,
-    ).unwrap();
-
-    let reference_surf = render_document(
-        &reference,
-        SurfaceSize(400, 400),
-        |_| (),
-        cairo::Rectangle {
-            x: 0.0,
-            y: 0.0,
-            width: 400.0,
-            height: 400.0,
-        },
-    )
-    .unwrap();
-
-    Reference::from_surface(reference_surf.into_image_surface().unwrap())
-        .compare(&output_surf)
-        .evaluate(&output_surf, "sepia_filter_func");
-}
+);