Rewrite reference processing code in preparation for opening/closing from comment references (#8261)

* Add a markdown stripper for mentions and xrefs

* Improve comments

* Small code simplification

* Move reference code to modules/references

* Fix typo

* Make MarkdownStripper return [][]byte

* Implement preliminary keywords parsing

* Add FIXME comment

* Fix comment

* make fmt

* Fix permissions check

* Fix text assumptions

* Fix imports

* Fix lint, fmt

* Fix unused import

* Add missing export comment

* Bypass revive on implemented interface

* Move mdstripper into its own package

* Support alphanumeric patterns

* Refactor FindAllMentions

* Move mentions test to references

* Parse mentions from reference package

* Refactor code to implement renderizable references

* Fix typo

* Move patterns and tests to the references package

* Fix nil reference

* Preliminary rendering attempt of closing keywords

* Normalize names, comments, general tidy-up

* Add CSS style for action keywords

* Fix permission for admin and owner

* Fix golangci-lint

* Fix golangci-lint

1 files changed, 296 insertions, 0 deletions

diff --git a/modules/references/references_test.go b/modules/references/references_test.go
new file mode 100644
index 0000000000..f8153ffe36
--- /dev/null
+++ b/modules/references/references_test.go
@@ -0,0 +1,296 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package references
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFindAllIssueReferences(t *testing.T) {
+
+	type result struct {
+		Index          int64
+		Owner          string
+		Name           string
+		Issue          string
+		Action         XRefAction
+		RefLocation    *RefSpan
+		ActionLocation *RefSpan
+	}
+
+	type testFixture struct {
+		input    string
+		expected []result
+	}
+
+	fixtures := []testFixture{
+		{
+			"Simply closes: #29 yes",
+			[]result{
+				{29, "", "", "29", XRefActionCloses, &RefSpan{Start: 15, End: 18}, &RefSpan{Start: 7, End: 13}},
+			},
+		},
+		{
+			"#123 no, this is a title.",
+			[]result{},
+		},
+		{
+			" #124 yes, this is a reference.",
+			[]result{
+				{124, "", "", "124", XRefActionNone, &RefSpan{Start: 0, End: 4}, nil},
+			},
+		},
+		{
+			"```\nThis is a code block.\n#723 no, it's a code block.```",
+			[]result{},
+		},
+		{
+			"This `#724` no, it's inline code.",
+			[]result{},
+		},
+		{
+			"This user3/repo4#200 yes.",
+			[]result{
+				{200, "user3", "repo4", "200", XRefActionNone, &RefSpan{Start: 5, End: 20}, nil},
+			},
+		},
+		{
+			"This [one](#919) no, this is a URL fragment.",
+			[]result{},
+		},
+		{
+			"This [two](/user2/repo1/issues/921) yes.",
+			[]result{
+				{921, "user2", "repo1", "921", XRefActionNone, nil, nil},
+			},
+		},
+		{
+			"This [three](/user2/repo1/pulls/922) yes.",
+			[]result{
+				{922, "user2", "repo1", "922", XRefActionNone, nil, nil},
+			},
+		},
+		{
+			"This [four](http://gitea.com:3000/user3/repo4/issues/203) yes.",
+			[]result{
+				{203, "user3", "repo4", "203", XRefActionNone, nil, nil},
+			},
+		},
+		{
+			"This [five](http://github.com/user3/repo4/issues/204) no.",
+			[]result{},
+		},
+		{
+			"This http://gitea.com:3000/user4/repo5/201 no, bad URL.",
+			[]result{},
+		},
+		{
+			"This http://gitea.com:3000/user4/repo5/pulls/202 yes.",
+			[]result{
+				{202, "user4", "repo5", "202", XRefActionNone, nil, nil},
+			},
+		},
+		{
+			"This http://GiTeA.COM:3000/user4/repo6/pulls/205 yes.",
+			[]result{
+				{205, "user4", "repo6", "205", XRefActionNone, nil, nil},
+			},
+		},
+		{
+			"Reopens #15 yes",
+			[]result{
+				{15, "", "", "15", XRefActionReopens, &RefSpan{Start: 8, End: 11}, &RefSpan{Start: 0, End: 7}},
+			},
+		},
+		{
+			"This closes #20 for you yes",
+			[]result{
+				{20, "", "", "20", XRefActionCloses, &RefSpan{Start: 12, End: 15}, &RefSpan{Start: 5, End: 11}},
+			},
+		},
+		{
+			"Do you fix user6/repo6#300 ? yes",
+			[]result{
+				{300, "user6", "repo6", "300", XRefActionCloses, &RefSpan{Start: 11, End: 26}, &RefSpan{Start: 7, End: 10}},
+			},
+		},
+		{
+			"For 999 #1235 no keyword, but yes",
+			[]result{
+				{1235, "", "", "1235", XRefActionNone, &RefSpan{Start: 8, End: 13}, nil},
+			},
+		},
+		{
+			"Which abc. #9434 same as above",
+			[]result{
+				{9434, "", "", "9434", XRefActionNone, &RefSpan{Start: 11, End: 16}, nil},
+			},
+		},
+		{
+			"This closes #600 and reopens #599",
+			[]result{
+				{600, "", "", "600", XRefActionCloses, &RefSpan{Start: 12, End: 16}, &RefSpan{Start: 5, End: 11}},
+				{599, "", "", "599", XRefActionReopens, &RefSpan{Start: 29, End: 33}, &RefSpan{Start: 21, End: 28}},
+			},
+		},
+	}
+
+	// Save original value for other tests that may rely on it
+	prevURL := setting.AppURL
+	setting.AppURL = "https://gitea.com:3000/"
+
+	for _, fixture := range fixtures {
+		expraw := make([]*rawReference, len(fixture.expected))
+		for i, e := range fixture.expected {
+			expraw[i] = &rawReference{
+				index:          e.Index,
+				owner:          e.Owner,
+				name:           e.Name,
+				action:         e.Action,
+				issue:          e.Issue,
+				refLocation:    e.RefLocation,
+				actionLocation: e.ActionLocation,
+			}
+		}
+		expref := rawToIssueReferenceList(expraw)
+		refs := FindAllIssueReferencesMarkdown(fixture.input)
+		assert.EqualValues(t, expref, refs, "Failed to parse: {%s}", fixture.input)
+		rawrefs := findAllIssueReferencesMarkdown(fixture.input)
+		assert.EqualValues(t, expraw, rawrefs, "Failed to parse: {%s}", fixture.input)
+	}
+
+	// Restore for other tests that may rely on the original value
+	setting.AppURL = prevURL
+
+	type alnumFixture struct {
+		input          string
+		issue          string
+		refLocation    *RefSpan
+		action         XRefAction
+		actionLocation *RefSpan
+	}
+
+	alnumFixtures := []alnumFixture{
+		{
+			"This ref ABC-123 is alphanumeric",
+			"ABC-123", &RefSpan{Start: 9, End: 16},
+			XRefActionNone, nil,
+		},
+		{
+			"This closes ABCD-1234 alphanumeric",
+			"ABCD-1234", &RefSpan{Start: 12, End: 21},
+			XRefActionCloses, &RefSpan{Start: 5, End: 11},
+		},
+	}
+
+	for _, fixture := range alnumFixtures {
+		found, ref := FindRenderizableReferenceAlphanumeric(fixture.input)
+		if fixture.issue == "" {
+			assert.False(t, found, "Failed to parse: {%s}", fixture.input)
+		} else {
+			assert.True(t, found, "Failed to parse: {%s}", fixture.input)
+			assert.Equal(t, fixture.issue, ref.Issue, "Failed to parse: {%s}", fixture.input)
+			assert.Equal(t, fixture.refLocation, ref.RefLocation, "Failed to parse: {%s}", fixture.input)
+			assert.Equal(t, fixture.action, ref.Action, "Failed to parse: {%s}", fixture.input)
+			assert.Equal(t, fixture.actionLocation, ref.ActionLocation, "Failed to parse: {%s}", fixture.input)
+		}
+	}
+}
+
+func TestRegExp_mentionPattern(t *testing.T) {
+	trueTestCases := []string{
+		"@Unknwon",
+		"@ANT_123",
+		"@xxx-DiN0-z-A..uru..s-xxx",
+		"   @lol   ",
+		" @Te-st",
+		"(@gitea)",
+		"[@gitea]",
+	}
+	falseTestCases := []string{
+		"@ 0",
+		"@ ",
+		"@",
+		"",
+		"ABC",
+		"/home/gitea/@gitea",
+		"\"@gitea\"",
+	}
+
+	for _, testCase := range trueTestCases {
+		res := mentionPattern.MatchString(testCase)
+		assert.True(t, res)
+	}
+	for _, testCase := range falseTestCases {
+		res := mentionPattern.MatchString(testCase)
+		assert.False(t, res)
+	}
+}
+
+func TestRegExp_issueNumericPattern(t *testing.T) {
+	trueTestCases := []string{
+		"#1234",
+		"#0",
+		"#1234567890987654321",
+		"  #12",
+		"#12:",
+		"ref: #12: msg",
+	}
+	falseTestCases := []string{
+		"# 1234",
+		"# 0",
+		"# ",
+		"#",
+		"#ABC",
+		"#1A2B",
+		"",
+		"ABC",
+	}
+
+	for _, testCase := range trueTestCases {
+		assert.True(t, issueNumericPattern.MatchString(testCase))
+	}
+	for _, testCase := range falseTestCases {
+		assert.False(t, issueNumericPattern.MatchString(testCase))
+	}
+}
+
+func TestRegExp_issueAlphanumericPattern(t *testing.T) {
+	trueTestCases := []string{
+		"ABC-1234",
+		"A-1",
+		"RC-80",
+		"ABCDEFGHIJ-1234567890987654321234567890",
+		"ABC-123.",
+		"(ABC-123)",
+		"[ABC-123]",
+		"ABC-123:",
+	}
+	falseTestCases := []string{
+		"RC-08",
+		"PR-0",
+		"ABCDEFGHIJK-1",
+		"PR_1",
+		"",
+		"#ABC",
+		"",
+		"ABC",
+		"GG-",
+		"rm-1",
+		"/home/gitea/ABC-1234",
+		"MY-STRING-ABC-123",
+	}
+
+	for _, testCase := range trueTestCases {
+		assert.True(t, issueAlphanumericPattern.MatchString(testCase))
+	}
+	for _, testCase := range falseTestCases {
+		assert.False(t, issueAlphanumericPattern.MatchString(testCase))
+	}
+}