FIN INIT

node_modules/yaml/dist/nodes/Alias.js

@@ -0,0 +1,116 @@
+'use strict';
+
+var anchors = require('../doc/anchors.js');
+var visit = require('../visit.js');
+var identity = require('./identity.js');
+var Node = require('./Node.js');
+var toJS = require('./toJS.js');
+
+class Alias extends Node.NodeBase {
+    constructor(source) {
+        super(identity.ALIAS);
+        this.source = source;
+        Object.defineProperty(this, 'tag', {
+            set() {
+                throw new Error('Alias nodes cannot have tags');
+            }
+        });
+    }
+    /**
+     * Resolve the value of this alias within `doc`, finding the last
+     * instance of the `source` anchor before this node.
+     */
+    resolve(doc, ctx) {
+        let nodes;
+        if (ctx?.aliasResolveCache) {
+            nodes = ctx.aliasResolveCache;
+        }
+        else {
+            nodes = [];
+            visit.visit(doc, {
+                Node: (_key, node) => {
+                    if (identity.isAlias(node) || identity.hasAnchor(node))
+                        nodes.push(node);
+                }
+            });
+            if (ctx)
+                ctx.aliasResolveCache = nodes;
+        }
+        let found = undefined;
+        for (const node of nodes) {
+            if (node === this)
+                break;
+            if (node.anchor === this.source)
+                found = node;
+        }
+        return found;
+    }
+    toJSON(_arg, ctx) {
+        if (!ctx)
+            return { source: this.source };
+        const { anchors, doc, maxAliasCount } = ctx;
+        const source = this.resolve(doc, ctx);
+        if (!source) {
+            const msg = `Unresolved alias (the anchor must be set before the alias): ${this.source}`;
+            throw new ReferenceError(msg);
+        }
+        let data = anchors.get(source);
+        if (!data) {
+            // Resolve anchors for Node.prototype.toJS()
+            toJS.toJS(source, null, ctx);
+            data = anchors.get(source);
+        }
+        /* istanbul ignore if */
+        if (!data || data.res === undefined) {
+            const msg = 'This should not happen: Alias anchor was not resolved?';
+            throw new ReferenceError(msg);
+        }
+        if (maxAliasCount >= 0) {
+            data.count += 1;
+            if (data.aliasCount === 0)
+                data.aliasCount = getAliasCount(doc, source, anchors);
+            if (data.count * data.aliasCount > maxAliasCount) {
+                const msg = 'Excessive alias count indicates a resource exhaustion attack';
+                throw new ReferenceError(msg);
+            }
+        }
+        return data.res;
+    }
+    toString(ctx, _onComment, _onChompKeep) {
+        const src = `*${this.source}`;
+        if (ctx) {
+            anchors.anchorIsValid(this.source);
+            if (ctx.options.verifyAliasOrder && !ctx.anchors.has(this.source)) {
+                const msg = `Unresolved alias (the anchor must be set before the alias): ${this.source}`;
+                throw new Error(msg);
+            }
+            if (ctx.implicitKey)
+                return `${src} `;
+        }
+        return src;
+    }
+}
+function getAliasCount(doc, node, anchors) {
+    if (identity.isAlias(node)) {
+        const source = node.resolve(doc);
+        const anchor = anchors && source && anchors.get(source);
+        return anchor ? anchor.count * anchor.aliasCount : 0;
+    }
+    else if (identity.isCollection(node)) {
+        let count = 0;
+        for (const item of node.items) {
+            const c = getAliasCount(doc, item, anchors);
+            if (c > count)
+                count = c;
+        }
+        return count;
+    }
+    else if (identity.isPair(node)) {
+        const kc = getAliasCount(doc, node.key, anchors);
+        const vc = getAliasCount(doc, node.value, anchors);
+        return Math.max(kc, vc);
+    }
+    return 1;
+}
+
+exports.Alias = Alias;