refactor: simplify diff-local to accept git ranges via --ref directly

Remove --base flag per review feedback. Git range syntax (main..feature,
main...feature) can be passed directly to --ref. The parseRefRange()
helper in the executor splits the range for git show on each side.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

CLAUDE.md

@@ -334,7 +334,7 @@ go build -o bin/mxcli ./cmd/mxcli
 | **Testing** | `mxcli test tests/ -p app.mpr` | `.test.mdl` / `.test.md` files, requires Docker |
 | **Diff** | `mxcli diff -p app.mpr changes.mdl` | Compare script against project state |
 | **Diff local** | `mxcli diff-local -p app.mpr --ref HEAD` | Git diff for MPR v2 projects |
-| **Diff revisions** | `mxcli diff-local -p app.mpr --base main --ref feature` | Compare two arbitrary git revisions |
+| **Diff revisions** | `mxcli diff-local -p app.mpr --ref main..feature` | Compare two arbitrary git revisions |
 | **OQL** | `mxcli oql -p app.mpr "SELECT ..."` | Query running Mendix runtime |
 | **Widgets** | `SHOW WIDGETS`, `UPDATE WIDGETS SET ...` | Widget discovery and bulk updates (experimental) |
 | **External SQL** | `SQL CONNECT`, `SQL <alias> SELECT ...`, `mxcli sql` | Direct SQL queries against PostgreSQL, Oracle, SQL Server (credential isolation) |

cmd/mxcli/cmd_diff.go

@@ -102,8 +102,7 @@ var diffLocalCmd = &cobra.Command{
 This command finds modified mxunit files in the mprcontents/ folder and shows
 the differences as MDL. Only works with MPR v2 format (Mendix 10.18+).
 
-Use --ref for single-ref comparison (working tree vs ref), or --base with --ref
-to compare two arbitrary revisions (e.g., main vs feature branch).
+The --ref flag accepts any git ref or range (e.g., HEAD, main, main..feature-branch).
 
 Examples:
   # Show uncommitted changes vs HEAD
@@ -115,19 +114,18 @@ Examples:
   # Compare against a branch
   mxcli diff-local -p app.mpr --ref main
 
-  # Compare two arbitrary revisions
-  mxcli diff-local -p app.mpr --base main --ref feature-branch
+  # Compare two arbitrary revisions (git range syntax)
+  mxcli diff-local -p app.mpr --ref main..feature-branch
 
-  # Compare two commits
-  mxcli diff-local -p app.mpr --base abc1234 --ref def5678
+  # Three-dot range (changes since common ancestor)
+  mxcli diff-local -p app.mpr --ref main...feature-branch
 
   # With structural format
   mxcli diff-local -p app.mpr --format struct --color
 `,
 	Run: func(cmd *cobra.Command, args []string) {
 		projectPath, _ := cmd.Flags().GetString("project")
 		ref, _ := cmd.Flags().GetString("ref")
-		base, _ := cmd.Flags().GetString("base")
 		format, _ := cmd.Flags().GetString("format")
 		useColor, _ := cmd.Flags().GetBool("color")
 		width, _ := cmd.Flags().GetInt("width")
@@ -142,13 +140,6 @@ Examples:
 			ref = "HEAD"
 		}
 
-		// Build the git ref spec
-		gitRef := ref
-		if base != "" {
-			// Two-revision comparison: base..ref
-			gitRef = base + ".." + ref
-		}
-
 		// Create executor and connect
 		exec, logger := newLoggedExecutor("subcommand")
 		defer logger.Close()
@@ -169,7 +160,7 @@ Examples:
 			Width:    width,
 		}
 
-		if err := exec.DiffLocal(gitRef, opts); err != nil {
+		if err := exec.DiffLocal(ref, opts); err != nil {
 			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
 			os.Exit(1)
 		}

cmd/mxcli/main.go

@@ -228,8 +228,7 @@ func init() {
 	diffCmd.Flags().IntP("width", "w", 120, "Terminal width for side-by-side format")
 
 	// Diff-local command flags
-	diffLocalCmd.Flags().StringP("ref", "r", "HEAD", "Git reference to compare against (target revision)")
-	diffLocalCmd.Flags().StringP("base", "b", "", "Base revision for two-revision diff (e.g., --base main --ref feature)")
+	diffLocalCmd.Flags().StringP("ref", "r", "HEAD", "Git ref or range (e.g., HEAD, main, main..feature)")
 	diffLocalCmd.Flags().StringP("format", "f", "unified", "Output format: unified, side, struct")
 	diffLocalCmd.Flags().BoolP("color", "", false, "Use colored output")
 	diffLocalCmd.Flags().IntP("width", "w", 120, "Terminal width for side-by-side format")

docs-site/src/appendixes/quick-reference.md

@@ -541,7 +541,7 @@ Cross-reference commands require `REFRESH CATALOG FULL` to populate reference da
 | Test | `mxcli test tests/ -p app.mpr` | `.test.mdl` / `.test.md` files |
 | Diff script | `mxcli diff -p app.mpr changes.mdl` | Compare script vs project |
 | Diff local | `mxcli diff-local -p app.mpr --ref HEAD` | Git diff for MPR v2 |
-| Diff revisions | `mxcli diff-local -p app.mpr --base main --ref feature` | Compare two git revisions |
+| Diff revisions | `mxcli diff-local -p app.mpr --ref main..feature` | Compare two git revisions |
 | OQL | `mxcli oql -p app.mpr "SELECT ..."` | Query running Mendix runtime |
 | External SQL | `mxcli sql --driver postgres --dsn '...' "SELECT 1"` | Direct database query |
 | Docker build | `mxcli docker build -p app.mpr` | Build with PAD patching |

docs-site/src/tools/diff.md

@@ -35,11 +35,11 @@ mxcli diff-local -p app.mpr --ref HEAD~1
 # Compare against a branch
 mxcli diff-local -p app.mpr --ref main
 
-# Compare two arbitrary revisions
-mxcli diff-local -p app.mpr --base main --ref feature-branch
+# Compare two arbitrary revisions (git range syntax)
+mxcli diff-local -p app.mpr --ref main..feature-branch
 
-# Compare two specific commits
-mxcli diff-local -p app.mpr --base abc1234 --ref def5678
+# Three-dot range (changes since common ancestor)
+mxcli diff-local -p app.mpr --ref main...feature-branch
 ```
 
 ### MPR v2 Requirement
@@ -75,8 +75,8 @@ mxcli diff-local -p app.mpr --ref HEAD~2
 
 ```bash
 # What changed between main and your feature branch
-mxcli diff-local -p app.mpr --base main --ref feature-branch
+mxcli diff-local -p app.mpr --ref main..feature-branch
 
 # Feed diff into an LLM for review
-mxcli diff-local -p app.mpr --base main --ref feature-branch > changes.diff
+mxcli diff-local -p app.mpr --ref main..feature-branch > changes.diff
 ```