`query_graph`: raw property reads work, but `toInteger(...)` returns empty strings and literal `RETURN` expressions fail parsing

[ehendrix23]

Hi, it appears that query_graph has at least two separate problems in its Cypher handling. Yes, the below is coming from AI but figured it would be best to provide the examples it tried and then what it should be then me. .

1. function casting with toInteger(...) returns empty strings instead of integers
2. literal expressions in RETURN fail parsing, even inside a valid MATCH ... RETURN ... query

This blocks normal numeric filtering and computed projections, for example class size calculations from start_line / end_line.

Environment

• MCP: codebase-memory-mcp
• Tool: query_graph

Minimal repros

1. Control case: raw property read works

MATCH (c:Class {name: '_PDFIngestJob'})
RETURN c.start_line AS start_line
LIMIT 1

Actual result

{"columns":["start_line"],"rows":[["905"]],"total":1}

2. Another raw property read also works

 MATCH (c:Class {name: '_PDFIngestJob'})
 RETURN c.end_line
 LIMIT 1

** Actual result**

  {"columns":["c.end_line"],"rows":[["7007"]],"total":1}

So raw reads are working, and the returned values appear to be strings.

3. Cast of a string literal is broken

 MATCH (c:Class {name: '_PDFIngestJob'})
 RETURN toInteger('905') AS n
 LIMIT 1

Actual result

 {"columns":["toInteger"],"rows":[[""]],"total":1}

Expected result

 {"columns":["n"],"rows":[[905]],"total":1}

4. Cast of a property is broken

 MATCH (c:Class {name: '_PDFIngestJob'})
 RETURN c.start_line AS start_line, toInteger(c.start_line) AS start_line_int
 LIMIT 1

Actual result

 {"columns":["start_line","toInteger"],"rows":[["905",""]],"total":1}

Observed issues in this result

• toInteger(...) returns "" instead of an integer
• the alias start_line_int is ignored, and the returned column name is "toInteger"

5. Literal expression in RETURN fails parsing

  MATCH (c:Class {name: '_PDFIngestJob'})
  RETURN 1
  LIMIT 1

Actual error

 expected token type 85, got 87 at pos 47

6. Arithmetic expression in RETURN fails parsing

 MATCH (c:Class {name: '_PDFIngestJob'})
 RETURN 1 + 1 AS two
 LIMIT 1

Actual error

expected token type 85, got 87 at pos 47

7. Bare RETURN query also parser-fails

RETURN 1 + 1 AS two

Actual error

expected token type 0, got 2 at pos 0

Why this matters

This prevents straightforward numeric queries such as:

 MATCH (c:Class)
 WHERE c.start_line <> '' AND c.end_line <> ''
 RETURN
   c.name,
   toInteger(c.end_line) - toInteger(c.start_line) + 1 AS line_count

or queries such as:

 MATCH (c:Class)
  WHERE c.start_line IS NOT NULL
    AND c.end_line IS NOT NULL
    AND (toInteger(c.end_line) - toInteger(c.start_line) + 1) > 1200
  RETURN
    c.name AS name,
    c.file_path AS file_path,
    c.start_line AS start_line,
    c.end_line AS end_line,
    (toInteger(c.end_line) - toInteger(c.start_line) + 1) AS line_count
  ORDER BY line_count DESC
  LIMIT 50

Without working casts and arithmetic, class-size and similar graph analyses have to be done outside the graph query.

Observed behavior summary

• raw property projection works
• numeric-looking properties come back as strings
• toInteger(...) executes but returns empty strings
• aliases on function expressions are not preserved in the returned columns
• literal expressions in RETURN fail parsing

Expected behavior

• toInteger('905') should return 905
• toInteger(c.start_line) should return an integer value
• aliases like AS n and AS start_line_int should be preserved in columns
• RETURN 1 and RETURN 1 + 1 AS two should parse and execute normally inside valid Cypher

Impact

This makes it impossible to do simple numeric filtering or derived calculations inside query_graph, including line-count filters for large classes/modules and similar structural analysis workflows.