fix(json): allow primitives at top level without separator (#3466)

denoland · Jun 27, 2023 · deddc2a · deddc2a
1 parent 0d6701a
commit deddc2a
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Showing 2 changed files with 108 additions and 6 deletions.
diff --git a/json/concatenated_json_parse_stream.ts b/json/concatenated_json_parse_stream.ts
@@ -4,10 +4,14 @@ import type { JsonValue, ParseStreamOptions } from "./common.ts";
 import { parse } from "./_common.ts";
 
 const blank = new Set(" \t\r\n");
-function isBrankChar(char: string) {
+function isBlankChar(char: string) {
   return blank.has(char);
 }
 
+const primitives = new Map(
+  (["null", "true", "false"] as const).map((v) => [v[0], v]),
+);
+
 /**
  * Stream to parse [Concatenated JSON](https://en.wikipedia.org/wiki/JSON_streaming#Concatenated_JSON).
  *
@@ -53,11 +57,35 @@ export class ConcatenatedJsonParseStream
     let nestCount = 0;
     let readingString = false;
     let escapeNext = false;
+    let readingPrimitive: false | "null" | "true" | "false" = false;
+    let positionInPrimitive = 0;
     for await (const string of src) {
       let sliceStart = 0;
       for (let i = 0; i < string.length; i++) {
         const char = string[i];
 
+        // We're reading a primitive at the top level
+        if (readingPrimitive) {
+          if (char === readingPrimitive[positionInPrimitive]) {
+            positionInPrimitive++;
+
+            // Emit the primitive when done reading
+            if (positionInPrimitive === readingPrimitive.length) {
+              yield parse(targetString + string.slice(sliceStart, i + 1));
+              hasValue = false;
+              readingPrimitive = false;
+              positionInPrimitive = 0;
+              targetString = "";
+              sliceStart = i + 1;
+            }
+          } else {
+            // If the primitive is malformed, keep reading, maybe the next characters can be useful in the syntax error.
+            readingPrimitive = false;
+            positionInPrimitive = 0;
+          }
+          continue;
+        }
+
         if (readingString) {
           if (char === '"' && !escapeNext) {
             readingString = false;
@@ -74,12 +102,13 @@ export class ConcatenatedJsonParseStream
           continue;
         }
 
-        // Parses number, true, false, null with a nesting level of 0.
-        // example: 'null["foo"]' => null, ["foo"]
-        // example: 'false{"foo": "bar"}' => false, {foo: "bar"}
+        // Parses number with a nesting level of 0.
+        // example: '0["foo"]' => 0, ["foo"]
+        // example: '3.14{"foo": "bar"}' => 3.14, {foo: "bar"}
         if (
           hasValue && nestCount === 0 &&
-          (char === "{" || char === "[" || char === '"' || char === " ")
+          (char === "{" || char === "[" || char === '"' || char === " " ||
+            char === "n" || char === "t" || char === "f")
         ) {
           yield parse(targetString + string.slice(sliceStart, i));
           hasValue = false;
@@ -105,6 +134,12 @@ export class ConcatenatedJsonParseStream
             break;
         }
 
+        if (nestCount === 0 && primitives.has(char)) {
+          // The first letter of a primitive at top level was found
+          readingPrimitive = primitives.get(char)!;
+          positionInPrimitive = 1;
+        }
+
         // parse object or array
         if (
           hasValue && nestCount === 0 &&
@@ -117,7 +152,7 @@ export class ConcatenatedJsonParseStream
           continue;
         }
 
-        if (!hasValue && !isBrankChar(char)) {
+        if (!hasValue && !isBlankChar(char)) {
           // We want to ignore the character string with only blank, so if there is a character other than blank, record it.
           hasValue = true;
         }

diff --git a/json/concatenated_json_parse_stream_test.ts b/json/concatenated_json_parse_stream_test.ts
@@ -114,6 +114,21 @@ Deno.test({
       ['null null"foo"'],
       [null, null, "foo"],
     );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["nullnull"],
+      [null, null],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["nullnull0"],
+      [null, null, 0],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ['nullnull"foo"'],
+      [null, null, "foo"],
+    );
 
     await assertValidParse(
       ConcatenatedJsonParseStream,
@@ -140,6 +155,21 @@ Deno.test({
       ['true true"foo"'],
       [true, true, "foo"],
     );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["truetrue"],
+      [true, true],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["truetrue0"],
+      [true, true, 0],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ['truetrue"foo"'],
+      [true, true, "foo"],
+    );
 
     await assertValidParse(
       ConcatenatedJsonParseStream,
@@ -166,6 +196,27 @@ Deno.test({
       ['false false"foo"'],
       [false, false, "foo"],
     );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["falsefalse"],
+      [false, false],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["falsefalse0"],
+      [false, false, 0],
+    );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ['falsefalse"foo"'],
+      [false, false, "foo"],
+    );
+
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ['nullfalsetrue0true"foo"falsenullnull'],
+      [null, false, true, 0, true, "foo", false, null, null],
+    );
   },
 });
 
@@ -212,6 +263,11 @@ Deno.test({
       ['{"foo": "bar"}{', '"foo": "bar"}'],
       [{ foo: "bar" }, { foo: "bar" }],
     );
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["tr", 'ue{"foo": "bar"}'],
+      [true, { foo: "bar" }],
+    );
   },
 });
 
@@ -237,6 +293,17 @@ Deno.test({
   },
 });
 
+Deno.test({
+  name: "[json] ConcatenatedJsonParseStream: primitives in containers",
+  async fn() {
+    await assertValidParse(
+      ConcatenatedJsonParseStream,
+      ["[ true ]"],
+      [[true]],
+    );
+  },
+});
+
 Deno.test({
   name: "[json] ConcatenatedJsonParseStream: halfway chunk",
   async fn() {