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Fix crash where lines appended to end of script file causes out of bounds exception #730

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Merged
merged 6 commits into from
Aug 28, 2018
Merged

Fix crash where lines appended to end of script file causes out of bounds exception #730

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4eed1bb
Fix crash where lines appended to end of script file cause out of bou…
Aug 23, 2018
08647af
Fix XML comment, add a test
Aug 23, 2018
6a17b4a
Add a test for the script, add an XML comment for the validation para…
Aug 23, 2018
7bdbc2d
Add new validate method as overload rather than optional parameter
Aug 23, 2018
e1cff3d
Add comments to explain ScriptFile position validation changes
rjmholt Aug 25, 2018
2bd9a30
Fix typo
rjmholt Aug 25, 2018
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120 changes: 80 additions & 40 deletions src/PowerShellEditorServices/Workspace/ScriptFile.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -114,7 +114,7 @@ public Token[] ScriptTokens
}

/// <summary>
/// Gets the array of filepaths dot sourced in this ScriptFile
/// Gets the array of filepaths dot sourced in this ScriptFile
/// </summary>
public string[] ReferencedFiles
{
Expand Down Expand Up @@ -227,7 +227,7 @@ public static IList<string> GetLines(string text)
}

/// <summary>
/// Deterines whether the supplied path indicates the file is an "untitled:Unitled-X"
/// Deterines whether the supplied path indicates the file is an "untitled:Unitled-X"
/// which has not been saved to file.
/// </summary>
/// <param name="path">The path to check.</param>
Expand Down Expand Up @@ -311,12 +311,38 @@ public void ValidatePosition(BufferPosition bufferPosition)
/// <param name="column">The 1-based column to be validated.</param>
public void ValidatePosition(int line, int column)
{
int maxLine = this.FileLines.Count;
ValidatePosition(line, column, isInsertion: false);
}

/// <summary>
/// Throws ArgumentOutOfRangeException if the given position is outside
/// of the file's buffer extents. If the position is for an insertion (an applied change)
/// the index may be 1 past the end of the file, which is just appended.
/// </summary>
/// <param name="line">The 1-based line to be validated.</param>
/// <param name="column">The 1-based column to be validated.</param>
/// <param name="isInsertion">If true, the position to validate is for an applied change.</param>
public void ValidatePosition(int line, int column, bool isInsertion)
{
// If new content is being added, VSCode sometimes likes to add it a (FileLines.Count + 1),
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@rkeithhill rkeithhill Aug 25, 2018 •
edited
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Minor nit, should this be "add it at …"?

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Are these comments ok @rkeithhill? Want to make sure I've put them where you want and saying enough, etc.

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Yes, they LGTM.

// which used to crash EditorServices. Now we append it on to the end of the file.
// See https://github.com/PowerShell/vscode-powershell/issues/1283
int maxLine = isInsertion ? this.FileLines.Count + 1 : this.FileLines.Count;
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I would add a code comment above this to make sure someone else doesn't think they see an off-by-one error with the this.FileLines.Count + 1 and attempt to fix it. :-)

if (line < 1 || line > maxLine)
{
throw new ArgumentOutOfRangeException($"Position {line}:{column} is outside of the line range of 1 to {maxLine}.");
}

// If we are inserting at the end of the file, the column should be 1
if (isInsertion && line == maxLine)
{
if (column != 1)
{
throw new ArgumentOutOfRangeException($"Insertion at the end of a file must occur at column 1");
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1 indexed columns???!?!?!? omg

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@tylerl0706 yep

$sb = [scriptblock]::Create('')
$sb.Ast.Extent.StartColumnNumber
# 1
$sb.Ast.Extent.StartLineNumber
# 1
$sb.Ast.Extent.StartOffset
# 0

}
return;
}

// The maximum column is either **one past** the length of the string
// or 1 if the string is empty.
string lineString = this.FileLines[line - 1];
Expand Down Expand Up @@ -347,51 +373,65 @@ public void ApplyChange(FileChange fileChange)
}
else
{
this.ValidatePosition(fileChange.Line, fileChange.Offset);
this.ValidatePosition(fileChange.EndLine, fileChange.EndOffset);

// Get the first fragment of the first line
string firstLineFragment =
this.FileLines[fileChange.Line - 1]
.Substring(0, fileChange.Offset - 1);

// Get the last fragment of the last line
string endLine = this.FileLines[fileChange.EndLine - 1];
string lastLineFragment =
endLine.Substring(
fileChange.EndOffset - 1,
(this.FileLines[fileChange.EndLine - 1].Length - fileChange.EndOffset) + 1);

// Remove the old lines
for (int i = 0; i <= fileChange.EndLine - fileChange.Line; i++)
{
this.FileLines.RemoveAt(fileChange.Line - 1);
}
this.ValidatePosition(fileChange.Line, fileChange.Offset, isInsertion: true);
this.ValidatePosition(fileChange.EndLine, fileChange.EndOffset, isInsertion: true);

// Build and insert the new lines
int currentLineNumber = fileChange.Line;
for (int changeIndex = 0; changeIndex < changeLines.Length; changeIndex++)
// VSCode sometimes likes to give the change start line as (FileLines.Count + 1).
// This used to crash EditorServices, but we now treat it as an append.
// See https://github.com/PowerShell/vscode-powershell/issues/1283
if (fileChange.Line == this.FileLines.Count + 1)
{
// Since we split the lines above using \n, make sure to
// trim the ending \r's off as well.
string finalLine = changeLines[changeIndex].TrimEnd('\r');

// Should we add first or last line fragments?
if (changeIndex == 0)
foreach (string addedLine in changeLines)
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Would there be a scenario where there's a changed line AND an added line?

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If so, the foreach might also need to handle the "between" logic as well.

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I guess a better question is... are the changed lines always consecutive

{
// Append the first line fragment
finalLine = firstLineFragment + finalLine;
string finalLine = addedLine.TrimEnd('\r');
this.FileLines.Add(finalLine);
}
if (changeIndex == changeLines.Length - 1)
}
// Otherwise, the change needs to go between existing content
else
{
// Get the first fragment of the first line
string firstLineFragment =
this.FileLines[fileChange.Line - 1]
.Substring(0, fileChange.Offset - 1);

// Get the last fragment of the last line
string endLine = this.FileLines[fileChange.EndLine - 1];
string lastLineFragment =
endLine.Substring(
fileChange.EndOffset - 1,
(this.FileLines[fileChange.EndLine - 1].Length - fileChange.EndOffset) + 1);

// Remove the old lines
for (int i = 0; i <= fileChange.EndLine - fileChange.Line; i++)
{
// Append the last line fragment
finalLine = finalLine + lastLineFragment;
this.FileLines.RemoveAt(fileChange.Line - 1);
}

this.FileLines.Insert(currentLineNumber - 1, finalLine);
currentLineNumber++;
}
// Build and insert the new lines
int currentLineNumber = fileChange.Line;
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maybe consider doing the -1 here instead of line 431. I think it's a little clearer.

for (int changeIndex = 0; changeIndex < changeLines.Length; changeIndex++)
{
// Since we split the lines above using \n, make sure to
// trim the ending \r's off as well.
string finalLine = changeLines[changeIndex].TrimEnd('\r');

// Should we add first or last line fragments?
if (changeIndex == 0)
{
// Append the first line fragment
finalLine = firstLineFragment + finalLine;
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do you think you could add a bit more comment?

Like... "append the first line fragment to the front of the change"
and... "append the last line fragment to the end of the change"

the code says that but the logic here is a tad complex

}
if (changeIndex == changeLines.Length - 1)
{
// Append the last line fragment
finalLine = finalLine + lastLineFragment;
}

this.FileLines.Insert(currentLineNumber - 1, finalLine);
currentLineNumber++;
}
}
}

// Parse the script again to be up-to-date
Expand Down
22 changes: 19 additions & 3 deletions test/PowerShellEditorServices.Test/Session/ScriptFileTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ namespace PSLanguageService.Test
{
public class ScriptFileChangeTests
{
private static readonly Version PowerShellVersion = new Version("5.0");
private static readonly Version PowerShellVersion = new Version("5.0");

[Fact]
public void CanApplySingleLineInsert()
Expand Down Expand Up @@ -127,6 +127,22 @@ public void CanApplyMultiLineDelete()
});
}

[Fact]
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😍

public void CanApplyEditsToEndOfFile()
{
this.AssertFileChange(
"line1\r\nline2\r\nline3\r\n\r\n",
"line1\r\nline2\r\nline3\r\n\r\n\r\n\r\n",
new FileChange
{
Line = 5,
EndLine = 5,
Offset = 1,
EndOffset = 1,
InsertString = "\r\n\r\n"
});
}

[Fact]
public void FindsDotSourcedFiles()
{
Expand All @@ -139,7 +155,7 @@ public void FindsDotSourcedFiles()

using (StringReader stringReader = new StringReader(exampleScriptContents))
{
ScriptFile scriptFile =
ScriptFile scriptFile =
new ScriptFile(
"DotSourceTestFile.ps1",
"DotSourceTestFile.ps1",
Expand Down Expand Up @@ -178,7 +194,7 @@ internal static ScriptFile CreateScriptFile(string initialString)
using (StringReader stringReader = new StringReader(initialString))
{
// Create an in-memory file from the StringReader
ScriptFile fileToChange =
ScriptFile fileToChange =
new ScriptFile(
"TestFile.ps1",
"TestFile.ps1",
Expand Down