Implement encoding/decoding of GeneratedRange flags

Author: szuend

src/codec.ts

@@ -27,6 +27,8 @@ export const enum OriginalScopeFlags {
 export const enum GeneratedRangeFlags {
   HAS_LINE = 0x1,
   HAS_DEFINITION = 0x2,
+  IS_STACK_FRAME = 0x4,
+  IS_HIDDEN = 0x8,
 }
 
 export const EmptyItem = Symbol("empty item");

src/decode/decode.ts

@@ -134,8 +134,10 @@ class Decoder {
               line: this.#rangeState.line,
               column: this.#rangeState.column,
             },
-            isStackFrame: false,
-            isHidden: false,
+            isStackFrame: Boolean(
+              item.flags & GeneratedRangeFlags.IS_STACK_FRAME,
+            ),
+            isHidden: Boolean(item.flags & GeneratedRangeFlags.IS_HIDDEN),
             values: [],
             children: [],
           };

src/encode/encoder.ts

@@ -151,6 +151,9 @@ export class Encoder {
       this.#rangeState.defScopeIdx = definitionIdx;
     }
 
+    if (range.isStackFrame) flags |= GeneratedRangeFlags.IS_STACK_FRAME;
+    if (range.isHidden) flags |= GeneratedRangeFlags.IS_HIDDEN;
+
     this.#encodeTag(EncodedTag.GENERATED_RANGE_START).#encodeUnsigned(flags);
     if (encodedLine > 0) this.#encodeUnsigned(encodedLine);
     this.#encodeUnsigned(encodedColumn);

src/roundtrip.test.ts

@@ -120,4 +120,16 @@ describe("round trip", () => {
 
     assertCodec(builder.build());
   });
+
+  it("handles the isStackFrame flag on GeneratedRanges", () => {
+    builder.startRange(0, 0, { isStackFrame: true }).endRange(0, 10);
+
+    assertCodec(builder.build());
+  });
+
+  it("handles the isHidden flag on GeneratedRanges", () => {
+    builder.startRange(0, 0, { isHidden: true }).endRange(0, 10);
+
+    assertCodec(builder.build());
+  });
 });