changes: Add command to create changelog from git

Author: mbland

scripts/changes

@@ -0,0 +1,45 @@
+#! /bin/bash
+#
+# Generates changelog notes from git history
+#
+# Usage: {{go}} {{cmd}} <start_ref> <end_ref>
+#
+# Where:
+#   <start_ref>  First commit reference to include (inclusive)
+#   <end_ref>    Last commit reference to include (exclusive)
+#
+# Example:
+#   To compile a list of changes for v1.0.1 since v1.0.0:
+#   {{go}} {{cmd}} v1.0.0 v1.0.1
+
+_changes() {
+  if [[ "$1" == '--complete' ]]; then
+    # Tab completions
+    local word_index="$2"
+    if [[ "$word_index" -gt 1 ]]; then
+      return 1
+    fi
+    shift
+    shift
+
+    local args=("$@")
+    compgen -W "$(git tag)" -- "${args[$word_index]}"
+    return
+  fi
+
+  local start_ref="$1"
+  local end_ref="$2"
+
+  if [[ -z "$start_ref" ]]; then
+    echo "Start ref not specified." >&2
+    return 1
+  elif [[ -z "$end_ref" ]]; then
+    echo "End ref not specified." >&2
+    return 1
+  fi
+
+  git log '--pretty=format:%h %an <%ae>%n        %s%n' \
+    "${start_ref}..${end_ref}^"
+}
+
+_changes "$@"

tests/changes.bats

@@ -0,0 +1,81 @@
+#! /usr/bin/env bats
+
+load environment
+load assertions
+load script_helper
+
+setup() {
+  mkdir -p "$TEST_GO_ROOTDIR/bin" "$TEST_GO_SCRIPTS_DIR"
+  cp "$_GO_ROOTDIR/scripts/changes" "$TEST_GO_SCRIPTS_DIR"
+  create_test_go_script 'PATH="$_GO_ROOTDIR/bin:$PATH"' '@go "$@"'
+}
+
+teardown() {
+  remove_test_go_rootdir
+}
+
+create_fake_git() {
+  local fake_git_path="$TEST_GO_ROOTDIR/bin/git"
+  local fake_git_impl=('#! /usr/bin/env bash' "$@")
+  local IFS=$'\n'
+
+  echo "${fake_git_impl[*]}" >"$fake_git_path"
+  chmod 700 "$fake_git_path"
+}
+
+@test "$SUITE: tab completions" {
+  local versions=('v1.0.0' 'v1.1.0')
+  local IFS=$'\n'
+  local fake_git_impl=(
+    "if [[ \"\$1\" == 'tag' ]]; then"
+    "  echo '${versions[*]}'"
+    '  exit 0'
+    'fi'
+    'exit 1'
+  )
+
+  create_fake_git "${fake_git_impl[@]}"
+  run "$TEST_GO_ROOTDIR/bin/git" 'tag'
+  assert_success "${versions[*]}"
+
+  run "$TEST_GO_SCRIPT" complete 1 changes ''
+  assert_success "${versions[*]}"
+
+  run "$TEST_GO_SCRIPT" complete 1 changes 'v1.0'
+  assert_success 'v1.0.0'
+
+  run "$TEST_GO_SCRIPT" complete 2 changes 'v1.0.0' 'v1.1'
+  assert_success 'v1.1.0'
+
+  run "$TEST_GO_SCRIPT" complete 3 changes 'v1.0.0' 'v1.1.0' ''
+  assert_failure ''
+}
+
+@test "$SUITE: error if no start ref" {
+  run "$TEST_GO_SCRIPT" changes
+  assert_failure "Start ref not specified."
+}
+
+@test "$SUITE: error if no end ref" {
+  run "$TEST_GO_SCRIPT" changes v1.0.0
+  assert_failure "End ref not specified."
+}
+
+@test "$SUITE: git log call is well-formed" {
+  local IFS=$'\n'
+  local fake_git_impl=(
+    "if [[ \"\$1\" == 'log' ]]; then"
+    '  shift'
+    "  IFS=\$'\\n'"
+    '  echo "$*"'
+    '  exit 0'
+    'fi'
+    'exit 1'
+  )
+
+  create_fake_git "${fake_git_impl[@]}"
+  run "$TEST_GO_SCRIPT" changes v1.0.0 v1.1.0
+  assert_success
+  assert_line_matches 0 '^--pretty=format:'
+  assert_line_matches 1 '^v1\.0\.0\.\.v1\.1\.0\^$'
+}