more tests

2 files changed, 201 insertions, 0 deletions

diff --git a/internal/textutil/textutil.go b/internal/textutil/textutil.go
new file mode 100644
index 0000000..7ef2680
--- /dev/null
+++ b/internal/textutil/textutil.go
@@ -0,0 +1,114 @@
+package textutil
+
+import "strings"
+
+// RenderTemplate performs simple {{var}} replacement in a template string.
+func RenderTemplate(t string, vars map[string]string) string {
+    if t == "" || len(vars) == 0 {
+        return t
+    }
+    out := t
+    for k, v := range vars {
+        out = strings.ReplaceAll(out, "{{"+k+"}}", v)
+    }
+    return out
+}
+
+// StripCodeFences removes surrounding Markdown triple-backtick fences.
+func StripCodeFences(s string) string {
+    t := strings.TrimSpace(s)
+    if t == "" {
+        return t
+    }
+    lines := strings.Split(t, "\n")
+    start := 0
+    for start < len(lines) && strings.TrimSpace(lines[start]) == "" {
+        start++
+    }
+    end := len(lines) - 1
+    for end >= 0 && strings.TrimSpace(lines[end]) == "" {
+        end--
+    }
+    if start >= len(lines) || end < 0 || start > end {
+        return t
+    }
+    first := strings.TrimSpace(lines[start])
+    last := strings.TrimSpace(lines[end])
+    if strings.HasPrefix(first, "```") && last == "```" && end > start {
+        inner := strings.Join(lines[start+1:end], "\n")
+        return inner
+    }
+    return t
+}
+
+// InstructionFromSelection extracts the first inline instruction and returns
+// (instruction, cleanedSelection). It detects markers on the earliest position
+// per line in precedence: strict ;text;, /* */, <!-- -->, //, #, --.
+func InstructionFromSelection(sel string) (string, string) {
+    lines := strings.Split(sel, "\n")
+    for idx, line := range lines {
+        if instr, cleaned, ok := FindFirstInstructionInLine(line); ok && strings.TrimSpace(instr) != "" {
+            lines[idx] = cleaned
+            return instr, strings.Join(lines, "\n")
+        }
+    }
+    return "", sel
+}
+
+// FindFirstInstructionInLine returns (instruction, cleaned, ok) for a single line.
+func FindFirstInstructionInLine(line string) (instr, cleaned string, ok bool) {
+    type cand struct{ start, end int; text string }
+    cands := []cand{}
+    if t, l, r, ok := FindStrictInlineTag(line); ok {
+        cands = append(cands, cand{start: l, end: r, text: t})
+    }
+    if i := strings.Index(line, "/*"); i >= 0 {
+        if j := strings.Index(line[i+2:], "*/"); j >= 0 {
+            start := i
+            end := i + 2 + j + 2
+            text := strings.TrimSpace(line[i+2 : i+2+j])
+            cands = append(cands, cand{start: start, end: end, text: text})
+        }
+    }
+    if i := strings.Index(line, "<!--"); i >= 0 {
+        if j := strings.Index(line[i+4:], "-->"); j >= 0 {
+            start := i
+            end := i + 4 + j + 3
+            text := strings.TrimSpace(line[i+4 : i+4+j])
+            cands = append(cands, cand{start: start, end: end, text: text})
+        }
+    }
+    if i := strings.Index(line, "//"); i >= 0 {
+        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
+    }
+    if i := strings.Index(line, "#"); i >= 0 {
+        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+1:])})
+    }
+    if i := strings.Index(line, "--"); i >= 0 {
+        cands = append(cands, cand{start: i, end: len(line), text: strings.TrimSpace(line[i+2:])})
+    }
+    if len(cands) == 0 { return "", line, false }
+    best := cands[0]
+    for _, c := range cands[1:] {
+        if c.start >= 0 && (best.start < 0 || c.start < best.start) { best = c }
+    }
+    cleaned = strings.TrimRight(line[:best.start]+line[best.end:], " \t")
+    return best.text, cleaned, true
+}
+
+// FindStrictInlineTag finds ;text; with no spaces after/before semicolons.
+func FindStrictInlineTag(line string) (text string, left, right int, ok bool) {
+    for i := 0; i < len(line); i++ {
+        if line[i] != ';' { continue }
+        if i+1 < len(line) && line[i+1] == ' ' { continue }
+        for j := i + 1; j < len(line); j++ {
+            if line[j] == ';' {
+                if j-1 >= 0 && line[j-1] == ' ' { continue }
+                inner := strings.TrimSpace(line[i+1 : j])
+                if inner != "" { return inner, i, j + 1, true }
+            }
+        }
+    }
+    return "", -1, -1, false
+}
+
diff --git a/internal/textutil/textutil_test.go b/internal/textutil/textutil_test.go
new file mode 100644
index 0000000..3a8cd90
--- /dev/null
+++ b/internal/textutil/textutil_test.go
@@ -0,0 +1,87 @@
+package textutil
+
+import (
+    "regexp"
+    "strings"
+    "testing"
+)
+
+func TestRenderTemplate_Basic(t *testing.T) {
+    out := RenderTemplate("Hello, {{name}}!", map[string]string{"name": "Hex"})
+    if out != "Hello, Hex!" {
+        t.Fatalf("render failed: %q", out)
+    }
+    // No vars
+    if RenderTemplate("x", nil) != "x" { t.Fatal("nil vars changed output") }
+}
+
+func TestStripCodeFences_Variants(t *testing.T) {
+    cases := []struct{ in, want string }{
+        {"```\ncode\n```", "code"},
+        {"```go\npackage x\n```", "package x"},
+        {"no fences", "no fences"},
+        {"\n\n```\ntrim\n```\n", "trim"},
+    }
+    for _, c := range cases {
+        if got := StripCodeFences(c.in); got != c.want {
+            t.Fatalf("strip mismatch: %q != %q", got, c.want)
+        }
+    }
+}
+
+func TestInstructionFromSelection_Markers(t *testing.T) {
+    inputs := []string{
+        ";do it;\ncode",
+        "/* fix */\ncode",
+        "<!-- doc -->\ncode",
+        "// change\ncode",
+        "# tweak\ncode",
+        "-- op\ncode",
+    }
+    for _, in := range inputs {
+        instr, cleaned := InstructionFromSelection(in)
+        if strings.TrimSpace(instr) == "" {
+            t.Fatalf("no instruction for input: %q", in)
+        }
+        // cleaned should not contain the instruction token
+        if strings.Contains(cleaned, instr) {
+            // Allow coincidence only if separated differently; require not exact match on same line
+            first := strings.Split(in, "\n")[0]
+            if strings.Contains(first, instr) {
+                t.Fatalf("instruction not removed: %q", cleaned)
+            }
+        }
+    }
+}
+
+func TestFindFirstInstructionInLine_EarliestWins(t *testing.T) {
+    // Both markers present, earliest should win (strict tag first)
+    line := ";first;  // later"
+    instr, cleaned, ok := FindFirstInstructionInLine(line)
+    if !ok || instr != "first" {
+        t.Fatalf("expected 'first', got %q ok=%v", instr, ok)
+    }
+    if strings.Contains(cleaned, instr) {
+        t.Fatalf("expected cleaned line to remove instr: %q", cleaned)
+    }
+}
+
+func TestFindStrictInlineTag(t *testing.T) {
+    if txt, l, r, ok := FindStrictInlineTag("pre;do;post"); !ok || txt != "do" || l != 3 || r != 7 {
+        t.Fatalf("strict tag parse failed: %q %d %d %v", txt, l, r, ok)
+    }
+    if _, _, _, ok := FindStrictInlineTag("; spaced ;"); ok {
+        t.Fatalf("should reject spaced strict tag")
+    }
+}
+
+// optional: ensure no ANSI codes appear in plain helpers
+func TestNoANSIInHelpers(t *testing.T) {
+    ansi := regexp.MustCompile(`\x1b\[[0-9;]*m`)
+    if ansi.MatchString(RenderTemplate("x", nil)) {
+        t.Fatalf("unexpected ansi in RenderTemplate")
+    }
+    if ansi.MatchString(StripCodeFences("x")) {
+        t.Fatalf("unexpected ansi in StripCodeFences")
+    }
+}