MATLAB language server - v1.3.14

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.3.14] - 2026-09-23
+
+### Fixed
+- Improved code suggestions when MATLAB is stopped in the debugger (Addresses [mathworks/MATLAB-extension-for-vscode#138](https://github.com/mathworks/MATLAB-extension-for-vscode/issues/251))
+
 ## [1.3.13] - 2026-07-28
 
 ### Added

matlab/+matlabls/+handlers/+testing/TestStreamingPlugin.m

@@ -47,11 +47,12 @@ function publishEvent(plugin, event)
     ts = pluginData.TestSuite;
     tc = ts.TestClass;
     if strlength(tc) > 0
-        testFile = fullfile(char(ts.BaseFolder), [char(tc) '.m']);
+        qualifiedName = char(tc);
     else
         parts = strsplit(char(pluginData.Name), '/');
-        testFile = fullfile(char(ts.BaseFolder), [parts{1} '.m']);
+        qualifiedName = parts{1};
     end
+    testFile = matlabls.handlers.testing.qualifiedNameToPath(char(ts.BaseFolder), qualifiedName);
 end
 
 

matlab/+matlabls/+handlers/+testing/discoverTests.m

@@ -26,6 +26,13 @@
             end
         end
         suite = [suites{:}];
+
+        % Before R2022a, TestSuite.fromFolder does not descend into namespace
+        % ("+") folders, so supplement the suite with any namespaced tests.
+        if strcmp(mode, 'folder') && isMATLABReleaseOlderThan('R2022a')
+            suite = [suite, discoverNamespacedTests(paths)];
+        end
+
         warnMsg = lastwarn;
         warnMsg = regexprep(warnMsg, '<a[^>]*>', '');
         warnMsg = strrep(warnMsg, '</a>', '');
@@ -45,11 +52,11 @@
             tc = suite(i).TestClass;
             if strlength(tc) > 0
                 testParentNames{i} = char(tc);
-                filenames{i} = fullfile(char(suite(i).BaseFolder), [char(tc) '.m']);
+                filenames{i} = matlabls.handlers.testing.qualifiedNameToPath(char(suite(i).BaseFolder), char(tc));
             else
                 parts = strsplit(fullName, '/');
                 testParentNames{i} = parts{1};
-                filenames{i} = fullfile(char(suite(i).BaseFolder), [parts{1} '.m']);
+                filenames{i} = matlabls.handlers.testing.qualifiedNameToPath(char(suite(i).BaseFolder), parts{1});
             end
 
             parenIdx = strfind(fullName, '(');
@@ -77,3 +84,17 @@
         result.warning = '';
     end
 end
+
+function suite = discoverNamespacedTests(paths)
+    % Build a suite from every test file within namespace ("+") folders under
+    % the given paths, adding each file directly since fromFolder skips them
+    % on releases before R2022a.
+    suite = matlab.unittest.Test.empty(1, 0);
+    for i = 1:numel(paths)
+        nsFiles = dir(fullfile(paths{i}, '**', '+*', '*.m'));
+        for j = 1:numel(nsFiles)
+            file = fullfile(nsFiles(j).folder, nsFiles(j).name);
+            suite = [suite, matlab.unittest.TestSuite.fromFile(file)]; %#ok<AGROW>
+        end
+    end
+end

matlab/+matlabls/+handlers/+testing/qualifiedNameToPath.m

@@ -0,0 +1,15 @@
+function p = qualifiedNameToPath(baseFolder, qualifiedName)
+
+    % Copyright 2026 The MathWorks, Inc.
+
+    parts = strsplit(qualifiedName, '.');
+    folders = strcat('+', parts(1:end-1));
+    p = fullfile(baseFolder, folders{:}, [parts{end} '.m']);
+
+    if ~isfile(p)
+        resolved = which(qualifiedName);
+        if ~isempty(resolved) && isfile(resolved)
+            p = resolved;
+        end
+    end
+end

matlab/+matlabls/+variableviewer/VariableViewerService.m

@@ -0,0 +1,86 @@
+classdef VariableViewerService < handle
+    % Pub/sub service for Variable Viewer communication with the VS Code extension.
+
+    % Copyright 2026 The MathWorks, Inc.
+
+    properties (Constant, Access = private)
+        ClientChannel = '/VariableViewer/ClientMsg'
+        ServerChannel = '/VariableViewer/ServerMsg'
+    end
+
+    methods (Static)
+        function setupListeners ()
+            matlabls.internal.CommunicationManager.subscribe( ...
+                matlabls.variableviewer.VariableViewerService.ClientChannel, ...
+                @matlabls.variableviewer.VariableViewerService.handleClientMessage);
+        end
+    end
+
+    methods (Static, Hidden)
+        function handleClientMessage (msg)
+            try
+                switch msg.type
+                    case 'QueryVariable'
+                        response = matlabls.variableviewer.getVariablePage(msg.varName, 1, 1);
+                    case 'QueryPage'
+                        response = matlabls.variableviewer.getVariablePage(msg.varName, msg.startRow, msg.startCol);
+                end
+                response = matlabls.variableviewer.VariableViewerService.buildResponse(response, msg.varName);
+                matlabls.internal.CommunicationManager.publish( ...
+                    matlabls.variableviewer.VariableViewerService.ServerChannel, response);
+            catch ME
+                errorResponse.type = "Error";
+                errorResponse.varName = string(msg.varName);
+                errorResponse.requestType = string(msg.type);
+                errorResponse.message = string(ME.message);
+                matlabls.internal.CommunicationManager.publish( ...
+                    matlabls.variableviewer.VariableViewerService.ServerChannel, errorResponse);
+            end
+        end
+    end
+
+    methods (Static, Access = private)
+        function response = buildResponse (response, varName)
+            response.type = "VariableResponse";
+            response.varName = string(varName);
+
+            % Normalize metadata.size to always serialize as an array
+            response.metadata.size = num2cell(response.metadata.size);
+
+            % Normalize labels to always serialize as arrays
+            if isfield(response, 'columns') && isfield(response.columns, 'labels')
+                response.columns.labels = matlabls.variableviewer.VariableViewerService.ensureCellArray(response.columns.labels);
+            end
+            if isfield(response, 'rows') && isfield(response.rows, 'labels')
+                response.rows.labels = matlabls.variableviewer.VariableViewerService.ensureCellArray(response.rows.labels);
+            end
+
+            % Normalize cells.data to always serialize as nested array
+            if isfield(response, 'cells') && isfield(response.cells, 'data')
+                response.cells.data = matlabls.variableviewer.VariableViewerService.ensureNestedCellArray(response.cells.data);
+            end
+        end
+
+        function out = ensureCellArray (structArray)
+            % Wrap struct array in a cell array so single-element arrays serialize as [{}] not {}
+            if isstruct(structArray)
+                out = num2cell(structArray);
+            else
+                out = structArray;
+            end
+        end
+
+        function out = ensureNestedCellArray (data)
+            % Ensure string matrix serializes as [["a","b"],["c","d"]] not ["a","b"]
+            if isstring(data)
+                nRows = size(data, 1);
+                out = cell(nRows, 1);
+                for r = 1:nRows
+                    out{r} = cellstr(data(r, :));
+                end
+            else
+                out = data;
+            end
+        end
+    end
+end

matlab/+matlabls/+variableviewer/getVariablePage.m

@@ -0,0 +1,189 @@
+function response = getVariablePage(varName, startRow, startCol, workspace)
+    %GETVARIABLEPAGE Return a page of data and metadata for a variable.
+    %
+    % response = getVariablePage("A", 1, 1)
+    % response = getVariablePage("T", 1, 1, "base")
+    %
+    % startRow and startCol are 1-based indices specifying the top-left
+    % corner of the page window into the variable's data.
+
+    % Copyright 2026 The MathWorks, Inc.
+
+    if nargin < 4
+        workspace = "base";
+    end
+
+    if ~isMATLABReleaseOlderThan("R2027b")
+        response = getPage(varName, startRow, startCol, workspace);
+    else
+        response = getPageLegacy(varName, startRow, startCol, workspace);
+    end
+end
+
+%% Constants
+
+function [rows, cols] = pageSize()
+    rows = 50;
+    cols = 20;
+end
+
+%% Support checks
+
+function tf = isResponseSupported(response)
+    metadata = response.metadata;
+    supportedClasses = ["double","single","int8","int16","int32","int64","uint8","uint16","uint32","uint64","logical","table"];
+
+    % Only 2D data is currently supported — check for sparse, tall, and N-D matrices
+    tf = ismember(metadata.dataType, supportedClasses) ...
+        && ~metadata.isSparse ...
+        && ~metadata.isTall ...
+        && numel(metadata.size) <= 2;
+end
+
+%% R2027a+ path — delegates to the internal pipeline
+function response = getPage(varName, startRow, startCol, workspace)
+    [pageRows, pageCols] = pageSize();
+    response = matlab.datatools.uiservices.variabledisplay.internal.pipeline.getVariableView(...
+        varName, ...
+        Workspace=workspace, ...
+        StartRow=startRow, ...
+        StartCol=startCol, ...
+        FlattenColumns=true, ...
+        PageSize=[pageRows, pageCols], ...
+        MetadataFcn=@addSparseTallFlags);
+
+    if ~isResponseSupported(response)
+        response.preview = unsupportedPreview(evalin(workspace, varName));
+    end
+end
+
+function metadata = addSparseTallFlags(metadata, varValue)
+    metadata.isSparse = issparse(varValue);
+    metadata.isTall = istall(varValue);
+end
+
+%% Legacy path — evalin once, build metadata, return cells or preview
+function response = getPageLegacy(varName, startRow, startCol, workspace)
+    [pageRows, pageCols] = pageSize();
+
+    varValue = evalin(workspace, varName);
+
+    response.metadata.size = size(varValue);
+    response.metadata.dataType = string(class(varValue));
+    response.metadata = addSparseTallFlags(response.metadata, varValue);
+
+    if ~isResponseSupported(response)
+        response.preview = unsupportedPreview(varValue);
+        return
+    end
+
+    if istable(varValue)
+        response = buildTablePage(response, varValue, startRow, startCol, pageRows, pageCols);
+    else
+        response = buildNumericPage(response, varValue, startRow, startCol, pageRows, pageCols);
+    end
+end
+
+function response = buildNumericPage(response, varValue, startRow, startCol, pageRows, pageCols)
+    [nRows, nCols] = size(varValue);
+
+    if nRows == 0 || nCols == 0
+        return
+    end
+
+    startRow = max(1, startRow);
+    startCol = max(1, startCol);
+
+    if startRow > nRows || startCol > nCols
+        error('getVariablePage:OutOfBounds', 'Requested page starts outside array bounds.');
+    end
+
+    endRow = min(startRow + pageRows - 1, nRows);
+    endCol = min(startCol + pageCols - 1, nCols);
+
+    page = varValue(startRow:endRow, startCol:endCol);
+    if islogical(page)
+        page = double(page);
+    end
+    response.cells.data = string(page);
+    response.cells.startRow = startRow;
+    response.cells.startCol = startCol;
+end
+
+function response = buildTablePage(response, varValue, startRow, startCol, pageRows, pageCols)
+    [nRows, nCols] = size(varValue);
+    varNames = varValue.Properties.VariableNames;
+    rowNames = varValue.Properties.RowNames;
+
+    if nRows == 0 || nCols == 0
+        for curCol = 1:min(pageCols, nCols)
+            response.columns.labels(curCol).id = string(curCol);
+            response.columns.labels(curCol).name = string(varNames{curCol});
+        end
+        return
+    end
+
+    startRow = max(1, startRow);
+    startCol = max(1, startCol);
+
+    if startRow > nRows || startCol > nCols
+        error('getVariablePage:OutOfBounds', 'Requested page starts outside table bounds.');
+    end
+
+    endRow = min(startRow + pageRows - 1, nRows);
+    endCol = min(startCol + pageCols - 1, nCols);
+
+    % Column labels — scoped to the page window
+    for curCol = startCol:endCol
+        localCol = curCol - startCol + 1;
+        response.columns.labels(localCol).id = string(curCol);
+        response.columns.labels(localCol).name = string(varNames{curCol});
+    end
+
+    % Row labels — scoped to the page window, only when table has RowNames
+    if ~isempty(rowNames)
+        for curRow = startRow:endRow
+            localRow = curRow - startRow + 1;
+            response.rows.labels(localRow).id = string(curRow);
+            response.rows.labels(localRow).name = string(rowNames{curRow});
+        end
+    end
+
+    % Flatten each cell to a display string
+    cellData = strings(endRow - startRow + 1, endCol - startCol + 1);
+    for c = startCol:endCol
+        for r = startRow:endRow
+            val = varValue{r, c};
+            if iscell(val) && isscalar(val)
+                val = val{1};
+            end
+            cellData(r - startRow + 1, c - startCol + 1) = flattenValue(val);
+        end
+    end
+
+    response.cells.data = cellData;
+    response.cells.startRow = startRow;
+    response.cells.startCol = startCol;
+end
+
+function s = unsupportedPreview(val)
+    s = strtrim(formattedDisplayText(val, 'SuppressMarkup', true));
+end
+
+function s = flattenValue(val)
+    if (isstring(val) && isscalar(val)) || ischar(val)
+        s = string(val);
+    elseif islogical(val) && isscalar(val)
+        if val
+            s = "true";
+        else
+            s = "false";
+        end
+    elseif isnumeric(val) && isscalar(val)
+        s = string(num2str(val));
+    elseif isscalar(val) && (isdatetime(val) || isduration(val) || iscalendarduration(val) || iscategorical(val))
+        s = string(val);
+    else
+        s = strjoin(string(size(val)), "x") + " " + string(class(val));
+    end
+end

matlab/initmatlabls.m

@@ -2,7 +2,7 @@ function initmatlabls (outFile)
     % Initializes a MATLAB® session to talk to a MATLAB language server.
     % Writes connection info to the outFile specified by the client
 
-    % Copyright 2022 - 2025 The MathWorks, Inc.
+    % Copyright 2022 - 2026 The MathWorks, Inc.
 
     try
         disp('matlabls: Beginning initialization')
@@ -32,7 +32,10 @@ function initmatlabls (outFile)
 
         % Initialize communication manager
         matlabls.internal.CommunicationManager.initialize();
-
+
+        % Initialize Variable Viewer pub/sub service
+        matlabls.variableviewer.VariableViewerService.setupListeners();
+
         if nargin == 1
             logConnectionData(outFile)
         end