[Feature] Network Inspector’s line-delimited JSON parsing logic does not handle blank lines correctly #3067

Description

Network Inspector supports parsing multiple independent JSON objects separated by newlines in request and response bodies.

However, the line-delimited parsing fallback fails when:

• Blank or whitespace-only lines appear between JSON objects.
• The body ends with an LF or CRLF newline.

Without these blank lines or trailing newlines, the same JSON objects are successfully parsed into an array.

Expected behavior

The line-delimited parsing fallback should ignore blank and whitespace-only lines, including those produced by trailing newlines, and return the parsed objects as an array:

[
    { "a": 1 },
    { "b": 2 }
]

Malformed JSON on a nonblank line should still produce an error.

Actual behavior

Blank lines or trailing newlines cause the line-delimited parsing fallback to throw a SyntaxError.

The outer formatter catches and logs the exception. If no subsequent formatter succeeds, the body is returned as raw text instead of a structured array.

Affected components

The issue affects two formatters in Network Inspector:

• JSON formatter: formats request and response bodies.
• GraphQL response formatter: formats response bodies.

A single valid JSON document containing formatting whitespace or a trailing newline is not affected.

Impact

Affected bodies lose their structured representation and fall back to raw-text output, preventing inspection as an object array.

The original body remains available, and the network request itself is unaffected.

Suggested fix

Handle blank and whitespace-only lines consistently in both line-delimited parsing fallbacks before parsing individual entries.

Add regression tests covering:

• Blank lines between JSON objects.
• Whitespace-only lines between JSON objects.
• Trailing LF and CRLF.
• Multiple JSON objects without blank lines.
• A single valid, pretty-printed JSON document with a trailing newline.
• Malformed JSON on a nonblank line.