[#674] Implement the introspective variant in tcr.revert()

- add tcr.introspectiveRevert()
- inject call to introspectiveRevert() in tcr.revert()
- tune and pass test case on revert for introspective variant

src/engine/tcr.go

@@ -595,7 +595,11 @@ func (tcr *TCREngine) commit(event events.TCREvent) {
 	tcr.handleError(tcr.vcsPushAuto(), false, status.VCSError)
 }
 
-func (tcr *TCREngine) revert(_ events.TCREvent) {
+func (tcr *TCREngine) revert(e events.TCREvent) {
+	if *tcr.variant == variant.Introspective {
+		_ = tcr.introspectiveRevert(e)
+		return
+	}
 	diffs, err := tcr.vcs.Diff()
 	tcr.handleError(err, false, status.VCSError)
 	if err != nil {
@@ -618,6 +622,26 @@ func (tcr *TCREngine) revert(_ events.TCREvent) {
 	}
 }
 
+func (tcr *TCREngine) introspectiveRevert(event events.TCREvent) (err error) {
+	// Commit changes with failure message into VCS index
+	err = tcr.vcs.Add()
+	if err != nil {
+		return err
+	}
+	err = tcr.vcs.Commit(false, tcr.wrapCommitMessages(commitMessageFail, &event)...)
+	if err != nil {
+		return err
+	}
+	// Rollback changes (both in VCS index and working tree)
+	err = tcr.vcs.RollbackLastCommit()
+	if err != nil {
+		return err
+	}
+	// Amend commit message on revert operation in VCS index
+	err = tcr.vcs.Commit(false, tcr.wrapCommitMessages(commitMessageRevert, nil)...)
+	return err
+}
+
 func (tcr *TCREngine) noFilesRevertedMessage() string {
 	if *tcr.variant == variant.Relaxed {
 		return "No file reverted (only test files were updated since last commit)"

src/engine/tcr_test.go

@@ -312,7 +312,6 @@ func Test_variant_specific_reverts(t *testing.T) {
 }
 
 func Test_introspective_variant(t *testing.T) {
-	t.Skip("work in progress")
 	tcr, vcsFake := initTCREngineWithFakesWithFileDiffs(
 		params.AParamSet(params.WithVariant(variant.Introspective.Name())),
 		nil, nil, nil, vcs.FileDiffs{
@@ -321,7 +320,12 @@ func Test_introspective_variant(t *testing.T) {
 		})
 
 	tcr.revert(*events.ATcrEvent())
-	assert.Equal(t, []fake.Command{fake.CommitCommand, fake.RollbackLastCommitCommand}, vcsFake.GetLastCommands(2))
+	assert.Equal(t, []fake.Command{
+		fake.AddCommand,
+		fake.CommitCommand,
+		fake.RollbackLastCommitCommand,
+		fake.CommitCommand,
+	}, vcsFake.GetLastCommands(4))
 }
 
 func Test_tcr_cycle_end_state(t *testing.T) {