1 files changed, 92 insertions, 0 deletions
diff --git a/vanilla/node_modules/css-tree/lib/generator/sourceMap.js b/vanilla/node_modules/css-tree/lib/generator/sourceMap.js
new file mode 100644
index 0000000..0c5ff27
--- /dev/null
+++ b/vanilla/node_modules/css-tree/lib/generator/sourceMap.js
@@ -0,0 +1,92 @@
+import { SourceMapGenerator } from 'source-map-js/lib/source-map-generator.js';
+
+const trackNodes = new Set(['Atrule', 'Selector', 'Declaration']);
+
+export function generateSourceMap(handlers) {
+    const map = new SourceMapGenerator();
+    const generated = {
+        line: 1,
+        column: 0
+    };
+    const original = {
+        line: 0, // should be zero to add first mapping
+        column: 0
+    };
+    const activatedGenerated = {
+        line: 1,
+        column: 0
+    };
+    const activatedMapping = {
+        generated: activatedGenerated
+    };
+    let line = 1;
+    let column = 0;
+    let sourceMappingActive = false;
+
+    const origHandlersNode = handlers.node;
+    handlers.node = function(node) {
+        if (node.loc && node.loc.start && trackNodes.has(node.type)) {
+            const nodeLine = node.loc.start.line;
+            const nodeColumn = node.loc.start.column - 1;
+
+            if (original.line !== nodeLine ||
+                original.column !== nodeColumn) {
+                original.line = nodeLine;
+                original.column = nodeColumn;
+
+                generated.line = line;
+                generated.column = column;
+
+                if (sourceMappingActive) {
+                    sourceMappingActive = false;
+                    if (generated.line !== activatedGenerated.line ||
+                        generated.column !== activatedGenerated.column) {
+                        map.addMapping(activatedMapping);
+                    }
+                }
+
+                sourceMappingActive = true;
+                map.addMapping({
+                    source: node.loc.source,
+                    original,
+                    generated
+                });
+            }
+        }
+
+        origHandlersNode.call(this, node);
+
+        if (sourceMappingActive && trackNodes.has(node.type)) {
+            activatedGenerated.line = line;
+            activatedGenerated.column = column;
+        }
+    };
+
+    const origHandlersEmit = handlers.emit;
+    handlers.emit = function(value, type, auto) {
+        for (let i = 0; i < value.length; i++) {
+            if (value.charCodeAt(i) === 10) { // \n
+                line++;
+                column = 0;
+            } else {
+                column++;
+            }
+        }
+
+        origHandlersEmit(value, type, auto);
+    };
+
+    const origHandlersResult = handlers.result;
+    handlers.result = function() {
+        if (sourceMappingActive) {
+            map.addMapping(activatedMapping);
+        }
+
+        return {
+            css: origHandlersResult(),
+            map
+        };
+    };
+
+    return handlers;
+};