Initial commit

Co-Authored-By: Eric Tuvesson <eric.tuvesson@gmail.com>
Co-Authored-By: mikaeltellhed <2311083+mikaeltellhed@users.noreply.github.com>
Co-Authored-By: kotte <14197736+mrtamagotchi@users.noreply.github.com>
Co-Authored-By: Anders Larsson <64838990+anders-topp@users.noreply.github.com>
Co-Authored-By: Johan  <4934465+joolsus@users.noreply.github.com>
Co-Authored-By: Tore Knudsen <18231882+torekndsn@users.noreply.github.com>
Co-Authored-By: victoratndl <99176179+victoratndl@users.noreply.github.com>

packages/noodl-git/src/merge-strategy.ts

@@ -0,0 +1,103 @@
+import { IMergeTreeEntry, MergeTreeError } from './core/models/merge';
+import { getFileContents } from './core/cat-file';
+import { addAll } from './core/add';
+
+import path from 'path';
+import fs from 'fs';
+
+function tryParseJson(str: string) {
+  try {
+    return JSON.parse(str);
+  } catch {
+    return null;
+  }
+}
+
+type JSON_OBJECT = {
+  [key: string]: any;
+};
+
+/** Merge the project.json file */
+export type MergeStrategyFunc = (ancestors: JSON_OBJECT, ours: JSON_OBJECT, theirs: JSON_OBJECT) => JSON_OBJECT;
+
+/**
+ * Defines the Noodl custom merge strategy.
+ */
+export class MergeStrategy {
+  constructor(
+    public readonly repositoryDir: string,
+    private readonly mergeProject: MergeStrategyFunc,
+    public readonly strategy: 'our' | 'their' = 'our'
+  ) {}
+
+  public async solveConflicts(tree: MergeTreeError) {
+    const projectJsonFiles = new Set<IMergeTreeEntry>(); //handle repos with multiple noodl projects
+    const otherFiles = new Set<IMergeTreeEntry>();
+
+    for (const entry of tree.conflictedEntries) {
+      if (entry.hasConflicts) {
+        const parent = entry.base || entry.our || entry.their;
+        if (parent.path === 'project.json' || parent.path.slice(-13) === '/project.json') {
+          projectJsonFiles.add(entry);
+        } else {
+          otherFiles.add(entry);
+        }
+      }
+    }
+
+    // Resolve conflicts
+    const projectPromises = Array.from(projectJsonFiles).map((x) => this.resolveProjectJsonConflict(x));
+    const otherFilePromises = Array.from(otherFiles).map((x) => this.resolveFileConflict(x));
+
+    const allPromises = [...projectPromises, ...otherFilePromises];
+    await Promise.all(allPromises);
+
+    // Mark all the file as resolved resolution
+    await addAll(this.repositoryDir);
+
+    // Return all files that were resolved
+    return [...projectJsonFiles, ...otherFiles];
+  }
+
+  private async resolveFileConflict(entry: IMergeTreeEntry) {
+    const parent = entry.base || entry.our || entry.their;
+    console.log('resolveFileConflict', parent.path);
+
+    const targetEntry = entry[this.strategy];
+    console.log('vcs: resolving file conflict', targetEntry.path, 'using', this.strategy);
+    const ourBlob = await getFileContents(this.repositoryDir, targetEntry.sha);
+
+    const absolutePath = path.join(this.repositoryDir, parent.path);
+    // Write our version of the file
+    await fs.promises.writeFile(absolutePath, ourBlob);
+  }
+
+  private async resolveProjectJsonConflict(entry: IMergeTreeEntry) {
+    const parent = entry.base || entry.our || entry.their;
+    console.log('resolveProjectJsonConflict', parent.path);
+
+    const results = await Promise.all([
+      entry.base ? getFileContents(this.repositoryDir, entry.base.sha) : Promise.resolve('{}'),
+      entry.our ? getFileContents(this.repositoryDir, entry.our.sha) : Promise.resolve('{}'),
+      entry.their ? getFileContents(this.repositoryDir, entry.their.sha) : Promise.resolve('{}')
+    ]);
+
+    const ancestor = tryParseJson(results[0].toString());
+    const ours = tryParseJson(results[1].toString());
+    const theirs = tryParseJson(results[2].toString());
+
+    if (!ancestor) {
+      throw new Error("Failed to solve project.json conflict. Couldn't parse ancestor: " + results[0].toString());
+    }
+    if (!ours) {
+      throw new Error("Failed to solve project.json conflict. Couldn't parse ours: " + results[1].toString());
+    } else if (!theirs) {
+      throw new Error("Failed to solve project.json conflict. Couldn't parse theirs: " + results[2].toString());
+    }
+
+    const mergedResult = this.mergeProject(ancestor, ours, theirs);
+
+    const absolutePath = path.join(this.repositoryDir, parent.path);
+    await fs.promises.writeFile(absolutePath, JSON.stringify(mergedResult));
+  }
+}