refactor(yaml): remove tag property

yaml/_dumper_state.ts

@@ -480,7 +480,6 @@ export class DumperState {
   condenseFlow: boolean;
   implicitTypes: Type<"scalar">[];
   explicitTypes: Type<KindType>[];
-  tag: string | null = null;
   duplicates: unknown[] = [];
   usedDuplicates: Set<unknown> = new Set();
   styleMap: ArrayObject<StyleVariant>;
@@ -590,7 +589,6 @@ export class DumperState {
   writeFlowSequence(level: number) {
     let _result = "";
     const object = this.dump;
-    const _tag = this.tag;
     for (let index = 0; index < object.length; index += 1) {
       // Write only valid elements.
       if (
@@ -605,14 +603,12 @@ export class DumperState {
       }
     }
 
-    this.tag = _tag;
     this.dump = `[${_result}]`;
   }
 
   writeBlockSequence(level: number, compact: boolean) {
     let _result = "";
     const object = this.dump;
-    const _tag = this.tag;
 
     for (let index = 0; index < object.length; index += 1) {
       // Write only valid elements.
@@ -637,13 +633,11 @@ export class DumperState {
       }
     }
 
-    this.tag = _tag;
     this.dump = _result || "[]"; // Empty sequence if no valid values.
   }
 
   writeFlowMapping(level: number) {
     let _result = "";
-    const _tag = this.tag;
     const object = this.dump;
     const objectKeyList = Object.keys(object);
 
@@ -686,13 +680,11 @@ export class DumperState {
       _result += pairBuffer;
     }
 
-    this.tag = _tag;
     this.dump = `{${_result}}`;
   }
 
-  writeBlockMapping(level: number, compact: boolean) {
+  writeBlockMapping(tag: string | null, level: number, compact: boolean) {
     const object = this.dump;
-    const _tag = this.tag;
     const objectKeyList = Object.keys(object);
     let _result = "";
 
@@ -727,7 +719,7 @@ export class DumperState {
         continue; // Skip this pair because of invalid key.
       }
 
-      const explicitPair = (this.tag !== null && this.tag !== "?") ||
+      const explicitPair = (tag !== null && tag !== "?") ||
         (this.dump && this.dump.length > 1024);
 
       if (explicitPair) {
@@ -766,39 +758,38 @@ export class DumperState {
       _result += pairBuffer;
     }
 
-    this.tag = _tag;
     this.dump = _result || "{}"; // Empty mapping if no valid pairs.
   }
 
-  detectType(explicit: boolean): boolean {
+  detectType(explicit: boolean): string | null {
     const object = this.dump;
     const typeList = explicit ? this.explicitTypes : this.implicitTypes;
 
+    let tag = null;
     for (const type of typeList) {
       if (type.predicate?.(object)) {
-        this.tag = explicit ? type.tag : "?";
+        tag = explicit ? type.tag : "?";
 
         if (type.represent) {
           const style = this.styleMap[type.tag]! || type.defaultStyle;
 
           if (typeof type.represent === "function") {
             this.dump = type.represent(object, style);
-            return true;
+            return tag;
           }
           if (Object.hasOwn(type.represent, style)) {
             this.dump = type.represent[style]!(object, style);
-            return true;
+            return tag;
           }
           throw new TypeError(
             `!<${type.tag}> tag resolver accepts not "${style}" style`,
           );
         }
 
-        return true;
+        return tag;
       }
     }
-
-    return false;
+    return tag;
   }
 
   // Serializes `object` and writes it to global `result`.
@@ -812,12 +803,9 @@ export class DumperState {
       isKey: boolean;
     },
   ): boolean {
-    this.tag = null;
     this.dump = object;
 
-    if (!this.detectType(false)) {
-      this.detectType(true);
-    }
+    const tag = this.detectType(false) ?? this.detectType(true) ?? null;
 
     if (block) {
       block = this.flowLevel < 0 || this.flowLevel > level;
@@ -834,7 +822,7 @@ export class DumperState {
     }
 
     if (
-      (this.tag !== null && this.tag !== "?") ||
+      (tag !== null && tag !== "?") ||
       duplicate ||
       (this.indent !== 2 && level > 0)
     ) {
@@ -849,7 +837,7 @@ export class DumperState {
       }
       if (isObject(this.dump) && !Array.isArray(this.dump)) {
         if (block && Object.keys(this.dump).length !== 0) {
-          this.writeBlockMapping(level, compact);
+          this.writeBlockMapping(tag, level, compact);
           if (duplicate) {
             this.dump = `&ref_${duplicateIndex}${this.dump}`;
           }
@@ -873,7 +861,7 @@ export class DumperState {
           }
         }
       } else if (typeof this.dump === "string") {
-        if (this.tag !== "?") {
+        if (tag !== "?") {
           this.writeScalar(this.dump, level, isKey);
         }
       } else {
@@ -885,8 +873,8 @@ export class DumperState {
         );
       }
 
-      if (this.tag !== null && this.tag !== "?") {
-        this.dump = `!<${this.tag}> ${this.dump}`;
+      if (tag !== null && tag !== "?") {
+        this.dump = `!<${tag}> ${this.dump}`;
       }
     }