Clean up ProjectDependencyFinder API to be self contained

src/Microsoft.DotNet.ProjectJsonMigration/ProjectDependencyFinder.cs

@@ -7,12 +7,48 @@ using Microsoft.DotNet.ProjectModel;
 using System.Linq;
 using System.IO;
 using Newtonsoft.Json.Linq;
+using Microsoft.DotNet.ProjectModel.Compilation;
+using Microsoft.DotNet.ProjectModel.Graph;
 
 namespace Microsoft.DotNet.ProjectJsonMigration
 {
     public class ProjectDependencyFinder 
     {
-        public Dictionary<string, ProjectDependency> FindPossibleProjectDependencies(string projectJsonFilePath)
+        public IEnumerable<ProjectDependency> ResolveProjectDependencies(ProjectContext projectContext, HashSet<string> preResolvedProjects=null)
+        {
+            preResolvedProjects = preResolvedProjects ?? new HashSet<string>();
+
+            var projectExports = projectContext.CreateExporter("_").GetDependencies();
+            var possibleProjectDependencies = 
+                FindPossibleProjectDependencies(projectContext.ProjectFile.ProjectFilePath);
+
+            var projectDependencies = new List<ProjectDependency>();
+            foreach (var projectExport in projectExports)
+            {
+                var projectExportName = projectExport.Library.Identity.Name;
+                ProjectDependency projectDependency;
+
+                if (!possibleProjectDependencies.TryGetValue(projectExportName, out projectDependency))
+                {
+                    if (projectExport.Library.Identity.Type.Equals(LibraryType.Project) 
+                        && !preResolvedProjects.Contains(projectExportName))
+                    {
+                        MigrationErrorCodes
+                            .MIGRATE1014($"Unresolved project dependency ({projectExportName})").Throw();
+                    }
+                    else
+                    {
+                        continue;
+                    }
+                }
+
+                projectDependencies.Add(projectDependency);
+            }
+
+            return projectDependencies;
+        }
+
+        private Dictionary<string, ProjectDependency> FindPossibleProjectDependencies(string projectJsonFilePath)
         {
             var projectDirectory = Path.GetDirectoryName(projectJsonFilePath);
 
@@ -112,7 +148,7 @@ namespace Microsoft.DotNet.ProjectJsonMigration
             return paths;
         }
 
-        public static string ResolveRootDirectory(string projectPath)
+        private static string ResolveRootDirectory(string projectPath)
         {
             var di = new DirectoryInfo(projectPath);
 

src/Microsoft.DotNet.ProjectJsonMigration/Rules/MigrateProjectDependenciesRule.cs

@@ -30,15 +30,11 @@ namespace Microsoft.DotNet.ProjectJsonMigration.Rules
         {
             _projectDirectory = migrationSettings.ProjectDirectory;
 
-            var possibleProjectDependencies = _projectDependencyFinder
-                .FindPossibleProjectDependencies(migrationRuleInputs.DefaultProjectContext.ProjectFile.ProjectFilePath);
-
             var migratedXProjDependencyPaths = MigrateXProjProjectDependencies(migrationSettings, migrationRuleInputs);
-            var migratedXProjDependencyNames = migratedXProjDependencyPaths.Select(p => Path.GetFileNameWithoutExtension(p));
+            var migratedXProjDependencyNames = new HashSet<string>(migratedXProjDependencyPaths.Select(p => Path.GetFileNameWithoutExtension(p)));
 
             AddPropertyTransformsToCommonPropertyGroup(migrationRuleInputs.CommonPropertyGroup);
             MigrateProjectJsonProjectDependencies(
-                possibleProjectDependencies, 
                 migrationRuleInputs.ProjectContexts, 
                 migratedXProjDependencyNames, 
                 migrationRuleInputs.OutputMSBuildProject);
@@ -88,37 +84,16 @@ namespace Microsoft.DotNet.ProjectJsonMigration.Rules
         }
 
         public void MigrateProjectJsonProjectDependencies(
-            Dictionary<string, ProjectDependency> possibleProjectDependencies,
             IEnumerable<ProjectContext> projectContexts,
-            IEnumerable<string> migratedXProjDependencyNames,
+            HashSet<string> migratedXProjDependencyNames,
             ProjectRootElement outputMSBuildProject)
         {
             foreach (var projectContext in projectContexts)
             {
+                var projectDependencies = _projectDependencyFinder.ResolveProjectDependencies(projectContext, migratedXProjDependencyNames);
                 var projectExports = projectContext.CreateExporter("_").GetDependencies();
 
-                var projectDependencyTransformResults = new List<ProjectItemElement>();
+                var projectDependencyTransformResults = projectDependencies.Select(p => ProjectDependencyTransform.Transform(p));
-                foreach (var projectExport in projectExports)
-                {
-                    var projectExportName = projectExport.Library.Identity.Name;
-                    ProjectDependency projectDependency;
-
-                    if (!possibleProjectDependencies.TryGetValue(projectExportName, out projectDependency))
-                    {
-                        if (projectExport.Library.Identity.Type.Equals(LibraryType.Project) 
-                            && !migratedXProjDependencyNames.Contains(projectExportName))
-                        {
-                            MigrationErrorCodes
-                                .MIGRATE1014($"Unresolved project dependency ({projectExportName})").Throw();
-                        }
-                        else
-                        {
-                            continue;
-                        }
-                    }
-
-                    projectDependencyTransformResults.Add(ProjectDependencyTransform.Transform(projectDependency));
-                }
                 
                 if (projectDependencyTransformResults.Any())
                 {