feat: suppress errors/warnings/diagnostics via comments (#385)

Author: parkuman

README.md

@@ -103,6 +103,18 @@ CircleCI Configuration files. It offers:
     <img src="https://images.ctfassets.net/il1yandlcjgk/3jXaQvhOQgayhV9O4nfAhZ/b6d55e689ddfcf7673ab7e9b76ba0a53/config_helper_autocomplete.png" alt="circleci-vscode-autocomplete" width="50%"/>
 </p>
 
+- **Diagnostic suppression** - allows you to suppress specific warnings and errors using special comments:
+  - `# cci-ignore` - suppress diagnostic on the same line
+  - `# cci-ignore-next-line` - suppress diagnostic on the next line
+  - `# cci-ignore-start` / `# cci-ignore-end` - suppress diagnostics in a range
+  - `# cci-ignore-file` - suppress all diagnostics in the file
+
+  Quick-fix code actions are available to automatically insert suppression comments.
+
+<p align="center">
+    <img src="https://images.ctfassets.net/il1yandlcjgk/2HsFnWKVRDavrKYN6gns6T/f30a25920e1a0c47fc7beaa2e81b93a0/cci-ignore-next-line.gif" alt="circleci-ignore-comments" width="50%"/>
+</p>
+
 ## <a name="platforms"></a>Platforms, Deployment and Package Managers
 
 The tool is deployed through

pkg/parser/suppression.go

@@ -0,0 +1,148 @@
+package parser
+
+import (
+	"regexp"
+
+	"github.com/CircleCI-Public/circleci-yaml-language-server/pkg/utils"
+	sitter "github.com/smacker/go-tree-sitter"
+	"go.lsp.dev/protocol"
+)
+
+type SuppressionInfo struct {
+	FileWideSuppression bool
+	SuppressedLines     map[uint32]bool
+	SuppressedRanges    []SuppressionRange
+}
+
+type SuppressionRange struct {
+	StartLine uint32
+	EndLine   uint32
+}
+
+var (
+	ignoreFileRegex       = regexp.MustCompile(`^\s*#\s*cci-ignore-file\s*$`)
+	ignoreInlineRegex     = regexp.MustCompile(`#\s*cci-ignore\s*$`)
+	ignoreNextLineRegex   = regexp.MustCompile(`^\s*#\s*cci-ignore-next-line\s*$`)
+	ignoreRangeStartRegex = regexp.MustCompile(`^\s*#\s*cci-ignore-start\s*$`)
+	ignoreRangeEndRegex   = regexp.MustCompile(`^\s*#\s*cci-ignore-end\s*$`)
+)
+
+func ParseSuppressionComments(doc *YamlDocument) *SuppressionInfo {
+	rootNode := doc.RootNode
+	suppressionInfo := &SuppressionInfo{
+		FileWideSuppression: false,
+		SuppressedLines:     make(map[uint32]bool),
+		SuppressedRanges:    []SuppressionRange{},
+	}
+
+	isRangeOpen := false
+	suppressionRange := SuppressionRange{}
+
+	// fetch all comments via tree-sitter and build up the suppression info
+	ExecQuery(rootNode, "(comment) @comment", func(match *sitter.QueryMatch) {
+		for _, capture := range match.Captures {
+			node := capture.Node
+			commentText := doc.GetNodeText(node)
+
+			// cci-ignore-file
+			if ignoreFileRegex.MatchString(commentText) {
+				suppressionInfo.FileWideSuppression = true
+				return
+			}
+
+			// cci-ignore
+			if ignoreInlineRegex.MatchString(commentText) {
+				line := doc.NodeToRange(node).Start.Line
+				suppressionInfo.SuppressedLines[line] = true
+			}
+
+			// cci-ignore-next-line
+			if ignoreNextLineRegex.MatchString(commentText) {
+				line := doc.NodeToRange(node).Start.Line
+				suppressionInfo.SuppressedLines[line+1] = true
+			}
+
+			// cci-ignore-start
+			if ignoreRangeStartRegex.MatchString(commentText) {
+				if isRangeOpen {
+					diagnostic := utils.CreateErrorDiagnosticFromNode(node, "cci-ignore-start must have a closing cci-ignore-end before trying to open a new ignore-range")
+					doc.addDiagnostic(diagnostic)
+					return
+				}
+				isRangeOpen = true
+				suppressionRange.StartLine = doc.NodeToRange(node).Start.Line
+			}
+
+			// cci-ignore-end
+			if ignoreRangeEndRegex.MatchString(commentText) {
+				if !isRangeOpen {
+					diagnostic := utils.CreateErrorDiagnosticFromNode(node, "cci-ignore-end must have an opening cci-ignore-start")
+					doc.addDiagnostic(diagnostic)
+					return
+				}
+				isRangeOpen = false
+				suppressionRange.EndLine = doc.NodeToRange(node).Start.Line
+				suppressionInfo.SuppressedRanges = append(suppressionInfo.SuppressedRanges, suppressionRange)
+			}
+		}
+	})
+
+	// Check if a range was left open without closing
+	if isRangeOpen {
+		// Create diagnostic at the cci-ignore-start line
+		diagnostic := protocol.Diagnostic{
+			Range: protocol.Range{
+				Start: protocol.Position{Line: suppressionRange.StartLine, Character: 0},
+				End:   protocol.Position{Line: suppressionRange.StartLine, Character: 100},
+			},
+			Severity: protocol.DiagnosticSeverityError,
+			Source:   "circleci",
+			Message:  "cci-ignore-start is missing a closing cci-ignore-end",
+		}
+		doc.addDiagnostic(diagnostic)
+	}
+
+	return suppressionInfo
+}
+
+// isDiagnosticSuppressed returns true if the diagnostic is suppressed by any one of the cci-ignore comments in the file
+func isDiagnosticSuppressed(suppressionInfo *SuppressionInfo, diagnostic protocol.Diagnostic) bool {
+	if suppressionInfo == nil {
+		return false
+	}
+
+	if suppressionInfo.FileWideSuppression {
+		return true
+	}
+
+	// NOTE: for a multi-line diagnostic, having `# cci-ignore-next-line` before it would ignore the whole diagnostic
+	if suppressionInfo.SuppressedLines[diagnostic.Range.Start.Line] {
+		return true
+	}
+
+	for _, suppressionRange := range suppressionInfo.SuppressedRanges {
+		if diagnosticOverlapsRange(suppressionRange, diagnostic) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// diagnosticOverlapsRange returns true if the diagnostic's line range overlaps with the cci-ignore suppression range
+func diagnosticOverlapsRange(r SuppressionRange, diagnostic protocol.Diagnostic) bool {
+	return r.StartLine <= diagnostic.Range.Start.Line && r.EndLine >= diagnostic.Range.Start.Line
+}
+
+// FilterSuppressedDiagnostics returns a new slice of diagnostics that are not suppressed by any of the cci-ignore comments in the file
+func FilterSuppressedDiagnostics(diagnostics []protocol.Diagnostic, suppression *SuppressionInfo) []protocol.Diagnostic {
+	remainingDiagnostics := []protocol.Diagnostic{}
+
+	for _, diagnostic := range diagnostics {
+		if !isDiagnosticSuppressed(suppression, diagnostic) {
+			remainingDiagnostics = append(remainingDiagnostics, diagnostic)
+		}
+	}
+
+	return remainingDiagnostics
+}