feat(resources): add CodeQL MaD (Models-as-Data) extensions support

Adds first-class support for authoring CodeQL data extensions (MaD) for
third-party libraries via a new `data_extension_development` workflow
prompt and per-language `codeql://languages/<lang>/library-modeling`
resources for every CodeQL language that supports MaD upstream
(cpp, csharp, go, java, javascript, python, ruby, rust, swift), plus a
shared `codeql://learning/data-extensions` overview resource.

Also includes review-feedback fixes: MaD tuple format updates in the
overview resource, prompt wiring + type fixes, and assorted client/
go lint and format cleanups.

Author: data-douser

CHANGELOG.md

@@ -14,6 +14,24 @@ release cadence.
 
 _Changes on `main` since the latest tagged release that have not yet been included in a stable release._
 
+### Added
+
+#### MCP Server Prompts
+
+| Prompt                       | Description                                                                                                                                                                                                                                 |
+| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `data_extension_development` | End-to-end workflow for authoring CodeQL data extensions (Models-as-Data) for third-party libraries; restricts `language` to MaD-supported languages. ([#266](https://github.com/advanced-security/codeql-development-mcp-server/pull/266)) |
+
+#### MCP Server Resources
+
+| URI                                         | Description                                                                                                                                                                                             |
+| ------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `codeql://learning/data-extensions`         | Models-as-Data (MaD) overview: YAML model formats, extensible predicates, and model-pack layout. ([#266](https://github.com/advanced-security/codeql-development-mcp-server/pull/266))                  |
+| `codeql://languages/rust/library-modeling`  | Rust-specific library-modeling guide (crate-path-based MaD format) for the `data_extension_development` workflow. ([#266](https://github.com/advanced-security/codeql-development-mcp-server/pull/266)) |
+| `codeql://languages/swift/library-modeling` | Swift-specific library-modeling guide (MaD tuple format) for the `data_extension_development` workflow. ([#266](https://github.com/advanced-security/codeql-development-mcp-server/pull/266))           |
+
+Every CodeQL language that supports Models-as-Data upstream (`cpp`, `csharp`, `go`, `java`, `javascript`, `python`, `ruby`, `rust`, `swift`) now has a registered `codeql://languages/<language>/library-modeling` resource. `actions` is intentionally excluded because it does not support data extensions.
+
 ### Fixed
 
 - **`query_results_cache_retrieve` rejected by GitHub Copilot Chat (HTTP 400 invalid schema)** — The `lineRange` and `resultIndices` parameters were defined with `z.tuple([...])`, which the MCP SDK serialized to a bare-array JSON Schema value (e.g. `[{"type":"integer"}, {"type":"integer"}]`). GitHub Copilot Chat enforces strict JSON Schema validation and rejected the entire `ql-mcp` server with `"... is not of type 'object', 'boolean'"`. Both parameters now use `z.object({ start, end })` so they serialize to a valid `type: "object"` JSON Schema. Tool callers must now pass `{ "lineRange": { "start": 1, "end": 10 } }` instead of `{ "lineRange": [1, 10] }`. ([#263](https://github.com/advanced-security/codeql-development-mcp-server/pull/263))

client/cmd/code_scanning_download_analysis.go

@@ -76,6 +76,6 @@ func runDownloadAnalysis(cmd *cobra.Command, _ []string) error {
 		}
 	}
 
-	fmt.Fprintf(cmd.OutOrStdout(), "Downloaded SARIF to %s (%d bytes)\n", outPath, len(sarif))
+	_, _ = fmt.Fprintf(cmd.OutOrStdout(), "Downloaded SARIF to %s (%d bytes)\n", outPath, len(sarif))
 	return nil
 }

client/cmd/code_scanning_list_alerts.go

@@ -75,11 +75,11 @@ func runListAlerts(cmd *cobra.Command, _ []string) error {
 	}
 
 	w := tabwriter.NewWriter(cmd.OutOrStdout(), 0, 4, 2, ' ', 0)
-	fmt.Fprintln(w, "NUM\tSTATE\tRULE\tSEVERITY\tFILE:LINE\tCREATED")
+	_, _ = fmt.Fprintln(w, "NUM\tSTATE\tRULE\tSEVERITY\tFILE:LINE\tCREATED")
 	for _, a := range alerts {
 		loc := a.MostRecentInstance.Location
 		locStr := fmt.Sprintf("%s:%d", loc.Path, loc.StartLine)
-		fmt.Fprintf(w, "%d\t%s\t%s\t%s\t%s\t%s\n",
+		_, _ = fmt.Fprintf(w, "%d\t%s\t%s\t%s\t%s\t%s\n",
 			a.Number, a.State, a.Rule.ID, a.Rule.Severity, locStr, a.CreatedAt)
 	}
 	return w.Flush()

client/cmd/code_scanning_list_analyses.go

@@ -72,9 +72,9 @@ func runListAnalyses(cmd *cobra.Command, _ []string) error {
 	}
 
 	w := tabwriter.NewWriter(cmd.OutOrStdout(), 0, 4, 2, ' ', 0)
-	fmt.Fprintln(w, "ID\tTOOL\tREF\tCATEGORY\tRESULTS\tRULES\tCREATED")
+	_, _ = fmt.Fprintln(w, "ID\tTOOL\tREF\tCATEGORY\tRESULTS\tRULES\tCREATED")
 	for _, a := range analyses {
-		fmt.Fprintf(w, "%d\t%s\t%s\t%s\t%d\t%d\t%s\n",
+		_, _ = fmt.Fprintf(w, "%d\t%s\t%s\t%s\t%d\t%d\t%s\n",
 			a.ID, a.Tool.Name, a.Ref, a.Category, a.ResultsCount, a.RulesCount, a.CreatedAt)
 	}
 	return w.Flush()

client/cmd/integration_tests.go

@@ -95,7 +95,7 @@ func runIntegrationTests(cmd *cobra.Command, _ []string) error {
 	// server/.tmp/) which causes log directory validation failures.
 	tmpBase := filepath.Join(repoRoot, ".tmp")
 	if os.Getenv("CODEQL_MCP_TMP_DIR") == "" {
-		os.Setenv("CODEQL_MCP_TMP_DIR", tmpBase)
+		_ = os.Setenv("CODEQL_MCP_TMP_DIR", tmpBase)
 	}
 
 	// Connect to MCP server

client/cmd/list.go

@@ -61,7 +61,7 @@ func runListTools(_ *cobra.Command, _ []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	tools, err := client.ListTools(ctx)
 	if err != nil {
@@ -87,15 +87,15 @@ func runListTools(_ *cobra.Command, _ []string) error {
 	}
 
 	w := tabwriter.NewWriter(os.Stdout, 0, 4, 2, ' ', 0)
-	fmt.Fprintf(w, "NAME\tDESCRIPTION\n")
+	_, _ = fmt.Fprintf(w, "NAME\tDESCRIPTION\n")
 	for _, t := range tools {
 		desc := t.Description
 		if len(desc) > 80 {
 			desc = desc[:77] + "..."
 		}
-		fmt.Fprintf(w, "%s\t%s\n", t.Name, desc)
+		_, _ = fmt.Fprintf(w, "%s\t%s\n", t.Name, desc)
 	}
-	w.Flush()
+	_ = w.Flush()
 	fmt.Printf("\n%d tools registered\n", len(tools))
 	return nil
 }
@@ -106,7 +106,7 @@ func runListPrompts(_ *cobra.Command, _ []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	prompts, err := client.ListPrompts(ctx)
 	if err != nil {
@@ -132,15 +132,15 @@ func runListPrompts(_ *cobra.Command, _ []string) error {
 	}
 
 	w := tabwriter.NewWriter(os.Stdout, 0, 4, 2, ' ', 0)
-	fmt.Fprintf(w, "NAME\tDESCRIPTION\n")
+	_, _ = fmt.Fprintf(w, "NAME\tDESCRIPTION\n")
 	for _, p := range prompts {
 		desc := p.Description
 		if len(desc) > 80 {
 			desc = desc[:77] + "..."
 		}
-		fmt.Fprintf(w, "%s\t%s\n", p.Name, desc)
+		_, _ = fmt.Fprintf(w, "%s\t%s\n", p.Name, desc)
 	}
-	w.Flush()
+	_ = w.Flush()
 	fmt.Printf("\n%d prompts registered\n", len(prompts))
 	return nil
 }
@@ -151,7 +151,7 @@ func runListResources(_ *cobra.Command, _ []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	resources, err := client.ListResources(ctx)
 	if err != nil {
@@ -178,15 +178,15 @@ func runListResources(_ *cobra.Command, _ []string) error {
 	}
 
 	w := tabwriter.NewWriter(os.Stdout, 0, 4, 2, ' ', 0)
-	fmt.Fprintf(w, "NAME\tURI\tDESCRIPTION\n")
+	_, _ = fmt.Fprintf(w, "NAME\tURI\tDESCRIPTION\n")
 	for _, r := range resources {
 		desc := r.Description
 		if len(desc) > 60 {
 			desc = desc[:57] + "..."
 		}
-		fmt.Fprintf(w, "%s\t%s\t%s\n", r.Name, r.URI, desc)
+		_, _ = fmt.Fprintf(w, "%s\t%s\t%s\n", r.Name, r.URI, desc)
 	}
-	w.Flush()
+	_ = w.Flush()
 	fmt.Printf("\n%d resources registered\n", len(resources))
 	return nil
 }

client/cmd/use_prompt.go

@@ -41,7 +41,7 @@ func runUsePrompt(_ *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	result, err := mcpclient.GetPrompt(ctx, client, promptName, params)
 	if err != nil {
@@ -58,11 +58,11 @@ func outputPromptMessages(result *mcpclient.PromptMessages) error {
 		if err != nil {
 			return err
 		}
-		fmt.Fprintln(os.Stdout, s)
+		_, _ = fmt.Fprintln(os.Stdout, s)
 	case "markdown":
-		fmt.Fprint(os.Stdout, mcpclient.FormatPromptMessagesMarkdown(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatPromptMessagesMarkdown(result))
 	default:
-		fmt.Fprint(os.Stdout, mcpclient.FormatPromptMessagesText(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatPromptMessagesText(result))
 	}
 	return nil
 }

client/cmd/use_resource.go

@@ -33,7 +33,7 @@ func runUseResource(_ *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	result, err := mcpclient.ReadResource(ctx, client, uri)
 	if err != nil {
@@ -50,11 +50,11 @@ func outputResourceContent(result *mcpclient.ResourceContent) error {
 		if err != nil {
 			return err
 		}
-		fmt.Fprintln(os.Stdout, s)
+		_, _ = fmt.Fprintln(os.Stdout, s)
 	case "markdown":
-		fmt.Fprint(os.Stdout, mcpclient.FormatResourceContentMarkdown(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatResourceContentMarkdown(result))
 	default:
-		fmt.Fprint(os.Stdout, mcpclient.FormatResourceContentText(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatResourceContentText(result))
 	}
 	return nil
 }

client/cmd/use_tool.go

@@ -42,7 +42,7 @@ func runUseTool(_ *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	defer client.Close()
+	defer func() { _ = client.Close() }()
 
 	result, err := mcpclient.CallTool(ctx, client, toolName, params)
 	if err != nil {
@@ -59,11 +59,11 @@ func outputToolResult(result *mcpclient.ToolResult) error {
 		if err != nil {
 			return err
 		}
-		fmt.Fprintln(os.Stdout, s)
+		_, _ = fmt.Fprintln(os.Stdout, s)
 	case "markdown":
-		fmt.Fprint(os.Stdout, mcpclient.FormatToolResultMarkdown(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatToolResultMarkdown(result))
 	default:
-		fmt.Fprint(os.Stdout, mcpclient.FormatToolResultText(result))
+		_, _ = fmt.Fprint(os.Stdout, mcpclient.FormatToolResultText(result))
 	}
 	if result.IsError {
 		return fmt.Errorf("tool returned error")

client/internal/mcp/primitives.go

@@ -195,10 +195,10 @@ func FormatResourceContentText(rc *ResourceContent) string {
 			sb.WriteString("\n---\n")
 		}
 		if item.URI != "" {
-			sb.WriteString(fmt.Sprintf("URI: %s\n", item.URI))
+			fmt.Fprintf(&sb, "URI: %s\n", item.URI)
 		}
 		if item.MIMEType != "" {
-			sb.WriteString(fmt.Sprintf("Type: %s\n", item.MIMEType))
+			fmt.Fprintf(&sb, "Type: %s\n", item.MIMEType)
 		}
 		sb.WriteString("\n")
 		sb.WriteString(item.Text)
@@ -211,13 +211,13 @@ func FormatResourceContentText(rc *ResourceContent) string {
 func FormatPromptMessagesText(pm *PromptMessages) string {
 	var sb strings.Builder
 	if pm.Description != "" {
-		sb.WriteString(fmt.Sprintf("Description: %s\n\n", pm.Description))
+		fmt.Fprintf(&sb, "Description: %s\n\n", pm.Description)
 	}
 	for i, msg := range pm.Messages {
 		if i > 0 {
 			sb.WriteString("\n---\n")
 		}
-		sb.WriteString(fmt.Sprintf("[%s]\n", msg.Role))
+		fmt.Fprintf(&sb, "[%s]\n", msg.Role)
 		sb.WriteString(msg.Content)
 		sb.WriteString("\n")
 	}
@@ -254,13 +254,13 @@ func FormatResourceContentMarkdown(rc *ResourceContent) string {
 func FormatPromptMessagesMarkdown(pm *PromptMessages) string {
 	var sb strings.Builder
 	if pm.Description != "" {
-		sb.WriteString(fmt.Sprintf("*%s*\n\n", pm.Description))
+		fmt.Fprintf(&sb, "*%s*\n\n", pm.Description)
 	}
 	for i, msg := range pm.Messages {
 		if i > 0 {
 			sb.WriteString("\n---\n\n")
 		}
-		sb.WriteString(fmt.Sprintf("### %s\n\n", msg.Role))
+		fmt.Fprintf(&sb, "### %s\n\n", msg.Role)
 		sb.WriteString(msg.Content)
 		sb.WriteString("\n")
 	}