Trailing comment causes parsing to die

[bgribaudo]

Preflight Checklist

• I have installed the latest version of Power Query SDK.
• I have checked existing resources, including the common issues and the release notes.
• I have searched for similar issues.

Power Query SDK

0.2.0

Regression From

No response

Platform

Windows

Architecture

x64

OS Version

No response

VSCode version

No response

PQSdkTool Path

No response

Bug Description

Attempting to evaluate an expression that ends with a comment dies with a syntax error.

Steps to Reproduce

In a connector project, set the .query.pq file's contents to the following, then attempt to evaluate the file:

1  //hi

Actual Experience

PQTest dies with a syntax error complaining that a semicolon was expected.

[10:18:12 AM]	[Info]	[Task found] c:\Users\ben\.vscode\extensions\powerquery.vscode-powerquery-sdk-0.2.0-win32-x64\.nuget\Microsoft.PowerQuery.SdkTools.2.111.5\tools\PQTest.exe run-test
				--extension "c:\Users\ben\Desktop\TestConnector\BenTest\bin\AnyCPU\Debug\BenTest.mez"
				--queryFile "c:\Users\ben\Desktop\TestConnector\BenTest\BenTest.query.pq"
				--prettyPrint
[10:18:12 AM]	[Error]	[Task exited abnormally] pqtest run-test pid(19256) exit(4294967291) stderr: Error: exception while running expression.: Token Semicolon expected. Start position: (2, 33). End position (2, 33).

Expected Experience

The above expression should evaluate successfully, returning 1.

Additional Context

No response

[bgribaudo]

I'm guessing that PQTest checks whether the .query.pq file's contents is a section document or solo expression; then, if the latter, it wraps that expression in the following template prior to evaluating it:

section PQTest-{{random guid}};

shared PQTest.RunTest = {expression from .query.pq file};

Since the solo expression ends on a single-line comment (6 //hi), after it is injected into the template, the ; at the template's end is considered commented out, hence the error.

If so, a simple fix for this error would be to move the last semicolon in the template down one line:

section PQTest-{{random guid}};

shared PQTest.RunTest = {expression from .query.pq file}
;

However, this won't resolve the similar error that occurs if the .query.pq file is instead set to 6 /* hi (ending in an incomplete multi-line comment).

[bgribaudo]

Another issue with the error messaging that results from the current approach is that the line/column numbering that is reported does not align with the contents of .query.pq. (Guessing this is because a hidden template is used, which adds some text to the M code, which throws numbering.)

Example: The error for the below expression is reported as starting on line 2, position 33—even though the expression contains only one line and well under 33 characters.

6 // hi

[bgribaudo]

Would it make sense to change the template used for solo expression evaluation to the following?

section PQTest;
shared PQTest.RunTest = Expression.Evaluate({reference to variable containing the solo expression}, #shared);

This way, the source code in .query.pq is evaluated exactly as written, without being textually interpreted into a template.

[mattmasson]

This should be resolved in the 2.112.x release of the SdkTools package.