test: add presentation layer tests

- Expand sharing_tests from 2 to 13 tests
- Add text_processor edge case tests
- Expand colors_tests from 2 to 11 tests
- Expand gradation_text_tests from 14 to 39 tests
- Add screen_transition_manager tests for all valid transitions

Author: unhappychoice

tests/unit/presentation/game/text_processor_tests.rs

@@ -191,3 +191,181 @@ fn is_at_end_of_line_content_at_end_of_text() {
     let result = TextProcessor::is_at_end_of_line_content(text, 5, &line_starts, &[]);
     assert!(!result); // Out of bounds
 }
+
+// ============================================
+// should_skip_character - middle newline
+// ============================================
+
+#[test]
+fn should_skip_character_newline_in_middle() {
+    let text = "hello\nworld";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    // Newline at position 5 is NOT the final newline, so should NOT be skipped
+    let result = TextProcessor::should_skip_character(text, 5, &line_starts, &[]);
+    assert!(!result);
+}
+
+#[test]
+fn should_skip_character_out_of_bounds() {
+    let text = "hello";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    let result = TextProcessor::should_skip_character(text, 100, &line_starts, &[]);
+    assert!(!result);
+}
+
+// ============================================
+// should_skip_character - whitespace before comment
+// ============================================
+
+#[test]
+fn should_skip_character_whitespace_before_comment() {
+    // "code  // comment" where comment starts at position 6
+    let text = "code  // comment";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    let comment_ranges = vec![(6, 16)];
+    // Position 4 is space before the comment
+    let result = TextProcessor::should_skip_character(text, 4, &line_starts, &comment_ranges);
+    assert!(result); // whitespace before comment should be skipped
+}
+
+#[test]
+fn should_skip_character_whitespace_not_before_comment() {
+    let text = "code  more";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    // Position 4 is space, but no comment follows
+    let result = TextProcessor::should_skip_character(text, 4, &line_starts, &[]);
+    assert!(!result);
+}
+
+// ============================================
+// process_challenge_text_with_comment_mapping - with comment ranges
+// ============================================
+
+#[test]
+fn process_with_comment_mapping_maps_comments_correctly() {
+    let text = "code // comment\nnext line";
+    let comment_ranges = vec![(5, 15)];
+    let (processed, mapped_ranges) =
+        TextProcessor::process_challenge_text_with_comment_mapping(text, &comment_ranges);
+    assert_eq!(processed, "code // comment\nnext line");
+    assert!(!mapped_ranges.is_empty());
+    // The comment range should be mapped to the same positions in processed text
+    let (start, end) = mapped_ranges[0];
+    assert_eq!(start, 5);
+    assert!(end > start);
+}
+
+#[test]
+fn process_with_comment_mapping_removes_empty_lines_and_adjusts_ranges() {
+    let text = "code // comment\n\nnext line";
+    let comment_ranges = vec![(5, 15)];
+    let (processed, mapped_ranges) =
+        TextProcessor::process_challenge_text_with_comment_mapping(text, &comment_ranges);
+    // Empty line should be removed
+    assert_eq!(processed, "code // comment\nnext line");
+    // Comment range should still be valid in the processed text
+    assert!(!mapped_ranges.is_empty());
+}
+
+#[test]
+fn process_with_comment_mapping_comment_in_removed_line() {
+    // Comment is entirely in an empty/removed section
+    let text = "\n// only comment\ncode";
+    // First line is empty, gets removed. Comment is on second line (positions 1-16)
+    let comment_ranges = vec![(1, 17)];
+    let (processed, mapped_ranges) =
+        TextProcessor::process_challenge_text_with_comment_mapping(text, &comment_ranges);
+    // "// only comment" line is not empty so should be kept
+    assert!(processed.contains("code"));
+    // mapped_ranges should still have the comment
+    let _ = mapped_ranges; // just checking it doesn't panic
+}
+
+#[test]
+fn process_with_comment_mapping_preserve_empty_with_comments() {
+    let text = "code // comment\n\nnext line";
+    let comment_ranges = vec![(5, 15)];
+    let (processed, mapped_ranges) =
+        TextProcessor::process_challenge_text_with_comment_mapping_preserve_empty(
+            text,
+            &comment_ranges,
+            true,
+        );
+    // With preserve_empty = true, empty line should be kept
+    assert!(processed.lines().count() >= 3);
+    assert!(!mapped_ranges.is_empty());
+}
+
+// ============================================
+// is_at_end_of_line_content - with comment ranges
+// ============================================
+
+#[test]
+fn is_at_end_of_line_content_before_comment() {
+    let text = "code // comment\nnext";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    let comment_ranges = vec![(5, 15)];
+    // Position 4 is space before comment - rest of line is comment only
+    let result = TextProcessor::is_at_end_of_line_content(text, 4, &line_starts, &comment_ranges);
+    assert!(result);
+}
+
+#[test]
+fn is_at_end_of_line_content_before_code() {
+    let text = "code more_code";
+    let line_starts = TextProcessor::calculate_line_starts(text);
+    let result = TextProcessor::is_at_end_of_line_content(text, 4, &line_starts, &[]);
+    assert!(!result);
+}
+
+// ============================================
+// is_rest_of_line_comment_only - edge cases
+// ============================================
+
+#[test]
+fn is_rest_of_line_comment_only_whitespace_then_comment() {
+    let text = "code   // comment";
+    let comment_ranges = vec![(7, 17)];
+    // Position 4 has spaces then comment
+    let result = TextProcessor::is_rest_of_line_comment_only(text, 4, &comment_ranges);
+    assert!(result);
+}
+
+#[test]
+fn is_rest_of_line_comment_only_out_of_bounds() {
+    let result = TextProcessor::is_rest_of_line_comment_only("hello", 100, &[]);
+    assert!(!result);
+}
+
+#[test]
+fn is_rest_of_line_comment_only_at_newline_boundary() {
+    let text = "code // comment\nnext";
+    let comment_ranges = vec![(5, 15)];
+    let result = TextProcessor::is_rest_of_line_comment_only(text, 5, &comment_ranges);
+    assert!(result);
+}
+
+// ============================================
+// process_challenge_text - more edge cases
+// ============================================
+
+#[test]
+fn process_challenge_text_only_whitespace_lines() {
+    let text = "   \n  \n   ";
+    let result = TextProcessor::process_challenge_text(text);
+    assert_eq!(result, "");
+}
+
+#[test]
+fn process_challenge_text_mixed_empty_and_content() {
+    let text = "\nline1\n\n\nline2\n";
+    let result = TextProcessor::process_challenge_text(text);
+    assert_eq!(result, "line1\nline2");
+}
+
+#[test]
+fn should_skip_final_newline_non_newline_char() {
+    let text = "hello";
+    let result = TextProcessor::should_skip_final_newline(text, 4);
+    assert!(!result); // 'o' is not a newline
+}

tests/unit/presentation/sharing_tests.rs

@@ -1,6 +1,7 @@
 use std::collections::HashSet;
 
-use gittype::presentation::sharing::SharingPlatform;
+use gittype::domain::models::{GitRepository, SessionResult};
+use gittype::presentation::sharing::{SharingPlatform, SharingService};
 
 #[test]
 fn sharing_platform_all_lists_every_variant_once() {
@@ -22,3 +23,146 @@ fn sharing_platform_name_matches_variant() {
     assert_eq!(SharingPlatform::LinkedIn.name(), "LinkedIn");
     assert_eq!(SharingPlatform::Facebook.name(), "Facebook");
 }
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+fn make_metrics(
+    score: f64,
+    cpm: f64,
+    valid_mistakes: usize,
+    invalid_mistakes: usize,
+) -> SessionResult {
+    let mut result = SessionResult::new();
+    result.session_score = score;
+    result.overall_cpm = cpm;
+    result.valid_mistakes = valid_mistakes;
+    result.invalid_mistakes = invalid_mistakes;
+    result
+}
+
+fn make_repo() -> GitRepository {
+    GitRepository {
+        user_name: "testuser".to_string(),
+        repository_name: "testrepo".to_string(),
+        remote_url: "https://github.com/testuser/testrepo".to_string(),
+        branch: Some("main".to_string()),
+        commit_hash: Some("abc".to_string()),
+        is_dirty: false,
+        root_path: None,
+    }
+}
+
+// ---------------------------------------------------------------------------
+// create_share_text tests
+// ---------------------------------------------------------------------------
+#[test]
+fn create_share_text_without_repo() {
+    let metrics = make_metrics(150.0, 300.0, 3, 2);
+    let text = SharingService::create_share_text(&metrics, &None);
+
+    assert!(text.contains("150"), "should contain score");
+    assert!(text.contains("300"), "should contain cpm");
+    assert!(text.contains("5"), "should contain total mistakes (3+2)");
+    assert!(text.contains("#gittype"));
+    assert!(text.contains("github.com/unhappychoice/gittype"));
+    // Should NOT contain repo info
+    assert!(!text.contains("testuser"));
+}
+
+#[test]
+fn create_share_text_with_repo() {
+    let metrics = make_metrics(200.0, 400.0, 1, 0);
+    let repo = make_repo();
+    let text = SharingService::create_share_text(&metrics, &Some(repo));
+
+    assert!(text.contains("200"), "should contain score");
+    assert!(text.contains("400"), "should contain cpm");
+    assert!(
+        text.contains("testuser/testrepo"),
+        "should contain repo info"
+    );
+    assert!(text.contains("#gittype"));
+}
+
+// ---------------------------------------------------------------------------
+// generate_share_url tests — one per platform
+// ---------------------------------------------------------------------------
+#[test]
+fn generate_share_url_x() {
+    let metrics = make_metrics(100.0, 250.0, 2, 1);
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::X, &None);
+    assert!(url.starts_with("https://x.com/intent/tweet?text="));
+    assert!(url.contains("gittype"));
+}
+
+#[test]
+fn generate_share_url_reddit() {
+    let metrics = make_metrics(100.0, 250.0, 2, 1);
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::Reddit, &None);
+    assert!(url.starts_with("https://www.reddit.com/submit?"));
+    assert!(url.contains("title="));
+    assert!(url.contains("selftext=true"));
+    assert!(url.contains("text="));
+}
+
+#[test]
+fn generate_share_url_linkedin() {
+    let metrics = make_metrics(100.0, 250.0, 2, 1);
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::LinkedIn, &None);
+    assert!(url.starts_with("https://www.linkedin.com/feed/"));
+    assert!(url.contains("shareActive=true"));
+}
+
+#[test]
+fn generate_share_url_facebook() {
+    let metrics = make_metrics(100.0, 250.0, 2, 1);
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::Facebook, &None);
+    assert!(url.starts_with("https://www.facebook.com/sharer/"));
+    assert!(url.contains("quote="));
+}
+
+#[test]
+fn generate_share_url_x_with_repo() {
+    let metrics = make_metrics(300.0, 600.0, 0, 0);
+    let repo = make_repo();
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::X, &Some(repo));
+    assert!(url.starts_with("https://x.com/intent/tweet?text="));
+    // URL-encoded repo name should be present
+    assert!(url.contains("testuser"));
+}
+
+#[test]
+fn generate_share_url_reddit_with_repo() {
+    let metrics = make_metrics(300.0, 600.0, 0, 0);
+    let repo = make_repo();
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::Reddit, &Some(repo));
+    assert!(url.contains("reddit.com"));
+    assert!(url.contains("title="));
+}
+
+#[test]
+fn generate_share_url_linkedin_with_repo() {
+    let metrics = make_metrics(300.0, 600.0, 0, 0);
+    let repo = make_repo();
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::LinkedIn, &Some(repo));
+    assert!(url.contains("linkedin.com"));
+}
+
+#[test]
+fn generate_share_url_facebook_with_repo() {
+    let metrics = make_metrics(300.0, 600.0, 0, 0);
+    let repo = make_repo();
+    let url = SharingService::generate_share_url(&metrics, &SharingPlatform::Facebook, &Some(repo));
+    assert!(url.contains("facebook.com"));
+}
+
+// ---------------------------------------------------------------------------
+// SharingPlatform Clone + Debug
+// ---------------------------------------------------------------------------
+#[test]
+fn sharing_platform_clone() {
+    let p = SharingPlatform::X;
+    let p2 = p.clone();
+    assert_eq!(p.name(), p2.name());
+}

tests/unit/presentation/tui/mod.rs

@@ -1 +1,2 @@
 pub mod screen_manager_tests;
+pub mod screen_transition_manager_tests;