Fix NRT warnings in Word converter

tools/MarkdownConverter.Tests/MarkdownSpecFileListTests.cs

@@ -1,4 +1,4 @@
-using MarkdownConverter.Spec;
+using MarkdownConverter.Spec;
 using Xunit;
 
 namespace MarkdownConverter.Tests;
@@ -8,6 +8,6 @@ public class MarkdownSpecFileListTests
     [Fact]
     public void EmptyListTest()
     {
-        Assert.Throws<ArgumentNullException>(() => MarkdownSpec.ReadFiles(null, new Reporter(TextWriter.Null)));
+        Assert.Throws<ArgumentNullException>(() => MarkdownSpec.ReadFiles(null!, new Reporter(TextWriter.Null)));
     }
-}
+}

tools/MarkdownConverter/Converter/MarkdownSpecConverter.cs

@@ -17,12 +17,12 @@ public static void ConvertToWord(MarkdownSpec spec, string templateFile, string
                 resultDoc.AddPart(part.OpenXmlPart, part.RelationshipId);
             }
 
-            var body = resultDoc.MainDocumentPart.Document.Body;
+            var body = resultDoc.MainDocumentPart!.Document.Body!;
 
             ReplaceTableOfContents(spec, body);
 
             var context = new ConversionContext();
-            context.MaxBookmarkId.Value = 1 + body.Descendants<BookmarkStart>().Max(bookmark => int.Parse(bookmark.Id));
+            context.MaxBookmarkId.Value = 1 + body.Descendants<BookmarkStart>().Max(bookmark => int.Parse(bookmark.Id!));
 
             foreach (var src in spec.Sources)
             {
@@ -72,9 +72,12 @@ private static void ReplaceTableOfContents(MarkdownSpec spec, Body body)
         }
     }
 
-    private static bool FindToc(Body body, out int ifirst, out int iLast, out string instr, out Paragraph secBreak)
+    private static bool FindToc(Body body, out int ifirst, out int iLast, out string? instr, out Paragraph? secBreak)
     {
-        ifirst = -1; iLast = -1; instr = null; secBreak = null;
+        ifirst = -1;
+        iLast = -1;
+        instr = null;
+        secBreak = null;
 
         for (int i = 0; i < body.ChildElements.Count; i++)
         {
@@ -86,23 +89,25 @@ private static bool FindToc(Body body, out int ifirst, out int iLast, out string
 
             // The TOC might be a simple field
             var sf = p.OfType<SimpleField>().FirstOrDefault();
-            if (sf != null && sf.Instruction.Value.Contains("TOC"))
+            if (sf?.Instruction?.Value?.Contains("TOC") == true)
             {
                 if (ifirst != -1)
                 {
                     throw new Exception("Found start of TOC and then another simple TOC");
                 }
 
-                ifirst = i; iLast = i; instr = sf.Instruction.Value;
+                ifirst = i;
+                iLast = i;
+                instr = sf.Instruction.Value;
                 break;
             }
 
             // or it might be a complex field
             var runElements = (from r in p.OfType<Run>() from e in r select e).ToList();
-            var f1 = runElements.FindIndex(f => f is FieldChar && (f as FieldChar).FieldCharType.Value == FieldCharValues.Begin);
-            var f2 = runElements.FindIndex(f => f is FieldCode && (f as FieldCode).Text.Contains("TOC"));
-            var f3 = runElements.FindIndex(f => f is FieldChar && (f as FieldChar).FieldCharType.Value == FieldCharValues.Separate);
-            var f4 = runElements.FindIndex(f => f is FieldChar && (f as FieldChar).FieldCharType.Value == FieldCharValues.End);
+            var f1 = runElements.FindIndex(f => f is FieldChar fc && fc.FieldCharType?.Value == FieldCharValues.Begin);
+            var f2 = runElements.FindIndex(f => f is FieldCode fc && fc.Text.Contains("TOC"));
+            var f3 = runElements.FindIndex(f => f is FieldChar fc && fc.FieldCharType?.Value == FieldCharValues.Separate);
+            var f4 = runElements.FindIndex(f => f is FieldChar fc && fc.FieldCharType?.Value == FieldCharValues.End);
 
             if (f1 != -1 && f2 != -1 && f3 != -1 && f2 > f1 && f3 > f2)
             {
@@ -111,7 +116,8 @@ private static bool FindToc(Body body, out int ifirst, out int iLast, out string
                     throw new Exception("Found start of TOC and then another start of TOC");
                 }
 
-                ifirst = i; instr = (runElements[f2] as FieldCode).Text;
+                ifirst = i;
+                instr = ((FieldCode) runElements[f2]).Text;
             }
             if (f4 != -1 && f4 > f1 && f4 > f2 && f4 > f3)
             {
@@ -141,7 +147,7 @@ private static bool FindToc(Body body, out int ifirst, out int iLast, out string
                 continue;
             }
 
-            var sp = p.ParagraphProperties.OfType<SectionProperties>().FirstOrDefault();
+            var sp = p.ParagraphProperties?.OfType<SectionProperties>().FirstOrDefault();
             if (sp == null)
             {
                 continue;

tools/MarkdownConverter/OptionExtensions.cs

@@ -4,7 +4,7 @@ namespace MarkdownConverter;
 
 internal static class OptionExtensions
 {
-    public static T Option<T>(this FSharpOption<T> o) where T : class
+    public static T? Option<T>(this FSharpOption<T> o) where T : class
     {
         if (FSharpOption<T>.GetTag(o) == FSharpOption<T>.Tags.None)
         {

tools/MarkdownConverter/Program.cs

@@ -36,7 +36,8 @@ static int Main(string[] args)
             else
             {
                 // Windows command-shell doesn't do globbing, so we have to do it ourselves
-                string dir = Path.GetDirectoryName(arg), filename = Path.GetFileName(arg);
+                string dir = Path.GetDirectoryName(arg) ?? throw new ArgumentException($"'{arg}' is a root directory");
+                string filename = Path.GetFileName(arg);
                 if (dir.Contains("*") || dir.Contains("?"))
                 {
                     Console.Error.WriteLine("Can't match wildcard directory names");
@@ -55,7 +56,8 @@ static int Main(string[] args)
         }
 
         var imdfiles = new List<string>();
-        string idocxfile = null, odocfile = null;
+        string? idocxfile = null;
+        string? odocfile = null;
         foreach (var ifile in ifiles)
         {
             var name = Path.GetFileName(ifile);
@@ -126,7 +128,7 @@ static int Main(string[] args)
             Console.WriteLine($"Writing '{Path.GetFileName(odocfile2)}'");
             try
             {
-                MarkdownSpecConverter.ConvertToWord(md, idocxfile, odocfile2, reporter);
+                MarkdownSpecConverter.ConvertToWord(md, idocxfile!, odocfile2, reporter);
             }
             catch (Exception ex)
             {
@@ -142,4 +144,4 @@ static int Main(string[] args)
         Console.WriteLine($"Warnings: {reporter.Warnings}");
         return reporter.Errors == 0 ? 0 : 1;
     }
-}
+}

tools/MarkdownConverter/Spec/MarkdownSpec.cs

@@ -55,9 +55,12 @@ private MarkdownSpec(IEnumerable<Tuple<string, MarkdownDocument>> sources, Repor
         }
     }
 
-    public static MarkdownSpec ReadFiles(IEnumerable<string> files, Reporter reporter, Func<string, TextReader> readerProvider = null)
+    public static MarkdownSpec ReadFiles(IEnumerable<string> files, Reporter reporter, Func<string, TextReader>? readerProvider = null)
     {
-        if (files is null) throw new ArgumentNullException(nameof(files));
+        if (files is null)
+        {
+            throw new ArgumentNullException(nameof(files));
+        }
 
         readerProvider ??= File.OpenText;
 

tools/MarkdownConverter/Spec/Reporter.cs

@@ -18,14 +18,14 @@ public class Reporter
     /// <summary>
     /// The parent reporter, if any. (This is to allow a complete error/warning count to be kept.)
     /// </summary>
-    private readonly Reporter parent;
+    private readonly Reporter? parent;
 
     public int Errors { get; private set; }
     public int Warnings { get; private set; }
 
     public SourceLocation Location { get; set; } = new SourceLocation(null, null, null, null);
 
-    private Reporter(Reporter parent, TextWriter writer, string filename)
+    private Reporter(Reporter? parent, TextWriter writer, string? filename)
     {
         this.parent = parent;
         this.writer = writer;
@@ -38,33 +38,33 @@ public Reporter(TextWriter writer) : this(null, writer, null)
 
     public Reporter WithFileName(string filename) => new Reporter(this, writer, filename);
 
-    public string CurrentFile => Location.File;
+    public string? CurrentFile => Location.File;
 
-    public SectionRef CurrentSection
+    public SectionRef? CurrentSection
     {
         get => Location.Section;
         set => Location = new SourceLocation(CurrentFile, value, CurrentParagraph, null);
     }
 
-    public MarkdownParagraph CurrentParagraph
+    public MarkdownParagraph? CurrentParagraph
     {
         get => Location.Paragraph;
         set => Location = new SourceLocation(CurrentFile, CurrentSection, value, null);
     }
 
-    public MarkdownSpan CurrentSpan
+    public MarkdownSpan? CurrentSpan
     {
         get => Location.Span;
         set => Location = new SourceLocation(CurrentFile, CurrentSection, CurrentParagraph, value);
     }
 
-    public void Error(string code, string msg, SourceLocation loc = null)
+    public void Error(string code, string msg, SourceLocation? loc = null)
     {
         IncrementErrors();
         Report(code, "ERROR", msg, loc?.Description ?? Location.Description);
     }
 
-    public void Warning(string code, string msg, SourceLocation loc = null)
+    public void Warning(string code, string msg, SourceLocation? loc = null)
     {
         IncrementWarnings();
         Report(code, "WARNING", msg, loc?.Description ?? Location.Description);

tools/MarkdownConverter/Spec/SectionRef.cs

@@ -7,7 +7,7 @@ public class SectionRef
     /// <summary>
     /// Section number, e.g. 10.1.2, or A.3 or null for sections without a number (e.g. Foreword).
     /// </summary>
-    public string Number { get;  }
+    public string? Number { get;  }
 
     /// <summary>
     /// Section title, e.g. "10.1.2 Goto Statement"
@@ -43,9 +43,9 @@ public SectionRef(MarkdownParagraph.Heading mdh, string filename, string bookmar
     {
         Level = mdh.size;
         var spans = mdh.body;
-        if (spans.Length == 1 && spans.First().IsLiteral)
+        if (spans.Length == 1 && spans.First() is MarkdownSpan.Literal literal)
         {
-            Title = MarkdownUtilities.UnescapeLiteral(spans.First() as MarkdownSpan.Literal).Trim();
+            Title = MarkdownUtilities.UnescapeLiteral(literal).Trim();
             if (char.IsDigit(Title[0]) || (Title[0] >= 'A' && Title[0] <= 'D' && Title[1] == '.'))
             {
                 var titleParts = Title.Split(new[] { ' ' }, 2);

tools/MarkdownConverter/Spec/SourceLocation.cs

@@ -6,13 +6,13 @@ namespace MarkdownConverter.Spec;
 
 public class SourceLocation
 {
-    public string File { get; }
-    public SectionRef Section { get; }
-    public MarkdownParagraph Paragraph { get; }
-    public MarkdownSpan Span { get; }
-    public string _loc; // generated lazily.
+    public string? File { get; }
+    public SectionRef? Section { get; }
+    public MarkdownParagraph? Paragraph { get; }
+    public MarkdownSpan? Span { get; }
+    public string? _loc; // generated lazily.
 
-    public SourceLocation(string file, SectionRef section, MarkdownParagraph paragraph, MarkdownSpan span)
+    public SourceLocation(string? file, SectionRef? section, MarkdownParagraph? paragraph, MarkdownSpan? span)
     {
         File = file;
         Section = section;
@@ -42,19 +42,21 @@ public string Description
             }
             else
             {
+                // TODO: Revisit all of the null-forgiving operator usage here at some point.
+
                 // Note: we now use the F# Markdown support for ranges, rather than finding text directly.
                 // This produces slightly weaker diagnostics than before, but it avoids an awful lot of fiddly fuzzy text matching code.
 
                 // TODO: Revisit SectionRef.Loc, possibly just exposing the paragraph directly.
-                var maybeRange = GetRange(Span);
+                var maybeRange = GetRange(Span!);
                 if (maybeRange != null)
                 {
                     var range = maybeRange.Value;
                     _loc = $"{File}({range.StartLine},{range.StartColumn},{range.EndLine},{range.EndColumn})";
                 }
                 else
                 {
-                    maybeRange = GetRange(Paragraph) ?? GetRange(Section.Loc.Paragraph);
+                    maybeRange = GetRange(Paragraph!) ?? GetRange(Section!.Loc.Paragraph!);
                     if (maybeRange == null)
                     {
                         // We don't have any line or column information. Just report the filename.